diff --git a/README.md b/README.md
index b341e72..1504ad6 100644
--- a/README.md
+++ b/README.md
@@ -42,21 +42,22 @@ Windows:
 clone or [download GitHub repository](https://github.com/felixlohmeier/openrefine-batch/archive/master.zip) to get example data
 
 ```
-./openrefine-batch.sh examples/powerhouse-museum/input/ examples/powerhouse-museum/config/ examples/powerhouse-museum/output/ 4G tsv --processQuotes=false --guessCellValueTypes=true
+./openrefine-batch.sh examples/powerhouse-museum/input/ examples/powerhouse-museum/config/ examples/powerhouse-museum/output/ examples/powerhouse-museum/cross/ 4G tsv --processQuotes=false --guessCellValueTypes=true
 ```
 
 #### Options
 
 ```
-./openrefine-batch.sh $inputdir $configdir $outputdir $ram $inputformat $inputoptions
+./openrefine-batch.sh $inputdir $configdir $outputdir $crossdir $ram $inputformat $inputoptions
 ```
 
-1. inputdir: path to directory with source files (multiple files may be imported into a single project by providing a zip or tar.gz archive)
-2. configdir: path to directory with OpenRefine transformation rules (json files)
-3. outputdir: path to directory for exported files (and temporary workspace)
-4. ram: maximum RAM for OpenRefine java heap space (default: 4G)
-5. inputformat: csv, tsv, xml, json, line-based, fixed-width, xlsx or ods
-6. inputoptions: several options provided by [openrefine-client](https://hub.docker.com/r/felixlohmeier/openrefine-client/)
+1. inputdir: path to directory with source files (multiple files may be imported into a single project [by providing a zip or tar.gz archive](https://github.com/OpenRefine/OpenRefine/wiki/Importers))
+2. configdir: path to directory with [OpenRefine transformation rules (json files)](http://kb.refinepro.com/2012/06/google-refine-json-and-my-notepad-or.html)
+3. outputdir: path to directory for exported files (and OpenRefine workspace)
+4. crossdir: path to directory with additional OpenRefine projects (will be copied to workspace before transformation step to support the [cross function](https://github.com/OpenRefine/OpenRefine/wiki/GREL-Other-Functions#crosscell-c-string-projectname-string-columnname))
+5. ram: maximum RAM for OpenRefine java heap space (default: 4G)
+6. inputformat: csv, tsv, xml, json, line-based, fixed-width, xlsx or ods
+7. inputoptions: several options provided by [openrefine-client](https://hub.docker.com/r/felixlohmeier/openrefine-client/)
 
 inputoptions (mandatory for xml, json, fixed-width, xslx, ods):
 * `--recordPath=RECORDPATH` (xml, json): please provide path in multiple arguments without slashes, e.g. /collection/record/ should be entered like this: `--recordPath=collection --recordPath=record`
@@ -83,69 +84,72 @@ more inputoptions (optional, only together with inputformat):
 The script uses `docker attach` to print log messages from OpenRefine server and `ps` to show statistics for each step. Here is a sample log:
 
 ```
-[00:08 felix ~/openrefine/openrefine-batch]$ ./openrefine-batch.sh examples/powerhouse-museum/input/ examples/powerhouse-museum/config/ examples/powerhouse-museum/output/ 4G tsv --processQuotes=false --guessCellValueTypes=true
-Input dir:              /home/felix/occcloud/Openness/Kunden+Projekte/OpenRefine/openrefine-batch/examples/powerhouse-museum/input
+[03:27 felix ~/openrefine-batch (master *)]$ ./openrefine-batch.sh examples/powerhouse-museum/input/ examples/powerhouse-museum/config/ examples/powerhouse-museum/output/ examples/powerhouse-museum/cross/ 4G tsv --processQuotes=false --guessCellValueTypes=true
+Input directory:        /home/felix/openrefine-batch/examples/powerhouse-museum/input
 Input files:            phm-collection.tsv
 Input format:           --format=tsv
-Input options:          --processQuotes=false --guessCellValueTypes=true        
+Input options:          --processQuotes=false --guessCellValueTypes=true            
+Config directory:       /home/felix/openrefine-batch/examples/powerhouse-museum/config
 Transformation rules:   phm-transform.json
+Cross directory:        /home/felix/openrefine-batch/examples/powerhouse-museum/cross
+Cross projects:         
 OpenRefine heap space:  4G
 OpenRefine version:     2.7rc1
-Docker container:       41ca6232-8484-40e0-a606-3bcbf29903f6
-Output directory:       /home/felix/occcloud/Openness/Kunden+Projekte/OpenRefine/openrefine-batch/examples/powerhouse-museum/output
+Docker container:       6b7eb36f-fc72-4040-b135-acee36948c13
+Output directory:       /home/felix/openrefine-batch/examples/powerhouse-museum/output
 
-begin: Mo 27. Feb 00:08:02 CET 2017
+begin: Mo 27. Feb 03:28:45 CET 2017
 
 start OpenRefine server...
 [sudo] password for felix: 
-fab9894d902372767cdb38d05b6e247dce722da22192d734862fc2f096a23d51
+92499ecd252a8768ea5b57e0be0fb30fe6340eab67d28b1be158e0ad01f79419
 
 import phm-collection.tsv...
-New project: 1719405033732
+New project: 2325849087106
 Number of rows: 75814
  STARTED     ELAPSED %MEM %CPU   RSS
-00:08:13       00:29 10.0  122 813604
+03:28:55       00:29 10.0  122 812208
 save project and restart OpenRefine server...
-23:08:46.130 [           ProjectManager] Saving all modified projects ... (4679ms)
-23:08:55.190 [        project_utilities] Saved project '1719405033732' (9060ms)
-41ca6232-8484-40e0-a606-3bcbf29903f6
-41ca6232-8484-40e0-a606-3bcbf29903f6
-6bb7ee1f1f2a1d09e191a3fadad9e26aaa89414b2c618a47d3d3ef7c040c6b1a
+02:29:28.170 [           ProjectManager] Saving all modified projects ... (4594ms)
+02:29:36.414 [        project_utilities] Saved project '2325849087106' (8244ms)
+6b7eb36f-fc72-4040-b135-acee36948c13
+6b7eb36f-fc72-4040-b135-acee36948c13
+f28de26b99475c4db09dbfb9ab3d445aa8127dedd08b8e729cb6b4d65c96bf38
 
-begin project 1719405033732 @ Mo 27. Feb 00:09:12 CET 2017
+begin project 2325849087106 @ Mo 27. Feb 03:29:52 CET 2017
 transform phm-transform.json...
-23:09:13.747 [                   refine] GET /command/core/get-models (2489ms)
-23:09:16.887 [                  project] Loaded project 1719405033732 from disk in 3 sec(s) (3140ms)
-23:09:17.140 [                   refine] POST /command/core/apply-operations (253ms)
+02:29:54.372 [                   refine] GET /command/core/get-models (2815ms)
+02:29:57.525 [                  project] Loaded project 2325849087106 from disk in 3 sec(s) (3153ms)
+02:29:57.640 [                   refine] POST /command/core/apply-operations (115ms)
  STARTED     ELAPSED %MEM %CPU   RSS
-00:08:57       01:10 20.1  124 1625788
+03:29:38       01:07 19.6  128 1588152
 save project and restart OpenRefine server...
-23:10:07.930 [           ProjectManager] Saving all modified projects ... (50790ms)
-23:10:15.173 [        project_utilities] Saved project '1719405033732' (7243ms)
-41ca6232-8484-40e0-a606-3bcbf29903f6
-41ca6232-8484-40e0-a606-3bcbf29903f6
-cc9c49dcaf54c720d915a55b4e646909f657fb6582c0ac3c9f069996b9cd0b53
-export to file 1719405033732.tsv...
-23:10:29.972 [                   refine] GET /command/core/get-models (4381ms)
-23:10:33.826 [                  project] Loaded project 1719405033732 from disk in 3 sec(s) (3854ms)
-23:10:34.123 [                   refine] GET /command/core/get-all-project-metadata (297ms)
-23:10:34.140 [                   refine] POST /command/core/export-rows/phm-collection.tsv.tsv (17ms)
+02:30:46.280 [           ProjectManager] Saving all modified projects ... (48640ms)
+02:30:53.404 [        project_utilities] Saved project '2325849087106' (7124ms)
+6b7eb36f-fc72-4040-b135-acee36948c13
+6b7eb36f-fc72-4040-b135-acee36948c13
+186b0bda0ca542642ce1875d55f8341648e05248eb359541b80191832783f40b
+export to file 2325849087106.tsv...
+02:31:08.149 [                   refine] GET /command/core/get-models (4039ms)
+02:31:11.485 [                  project] Loaded project 2325849087106 from disk in 3 sec(s) (3336ms)
+02:31:11.756 [                   refine] GET /command/core/get-all-project-metadata (271ms)
+02:31:11.774 [                   refine] POST /command/core/export-rows/phm-collection.tsv.tsv (18ms)
  STARTED     ELAPSED %MEM %CPU   RSS
-00:10:17       02:01 12.8 27.2 1041596
-save project and restart OpenRefine server...
-41ca6232-8484-40e0-a606-3bcbf29903f6
-41ca6232-8484-40e0-a606-3bcbf29903f6
-8e1febaf862c2e0bb162c6dfe968015b54f600d6b45f8d1a401b74e7285bc521
-finished project 1719405033732 @ Mo 27. Feb 00:12:36 CET 2017
-
-cleanup...
-41ca6232-8484-40e0-a606-3bcbf29903f6
-41ca6232-8484-40e0-a606-3bcbf29903f6
+03:30:55       01:59 11.6 28.6 942900
+restart OpenRefine server...
+6b7eb36f-fc72-4040-b135-acee36948c13
+6b7eb36f-fc72-4040-b135-acee36948c13
+eb0f91675b5fbf21b4c17cceb6d93146876ea19316b7ab44af78a36f64ff1037
+finished project 2325849087106 @ Mo 27. Feb 03:33:11 CET 2017
 
 output (number of lines / size in bytes):
-  167017 60527726 /home/felix/occcloud/Openness/Kunden+Projekte/OpenRefine/openrefine-batch/examples/powerhouse-museum/output/1719405033732.tsv
+  167017 60527726 /home/felix/openrefine-batch/examples/powerhouse-museum/output/2325849087106.tsv
 
-finish: Mo 27. Feb 00:12:42 CET 2017
+cleanup...
+6b7eb36f-fc72-4040-b135-acee36948c13
+6b7eb36f-fc72-4040-b135-acee36948c13
+
+finish: Mo 27. Feb 03:33:17 CET 2017
 ```
 
 ### Todo
@@ -153,6 +157,7 @@ finish: Mo 27. Feb 00:12:42 CET 2017
 - [ ] howto for installation on Mac and Windows
 - [ ] howto for extracting input options from OpenRefine GUI with Firefox network monitor
 - [ ] use getopts for parsing of arguments
+- [ ] add option to delete openrefine projects in output directory
 - [ ] provide more example data from other OpenRefine tutorials
 
 ### Licensing
diff --git a/openrefine-batch.sh b/openrefine-batch.sh
index 80450c2..47e270d 100755
--- a/openrefine-batch.sh
+++ b/openrefine-batch.sh
@@ -1,23 +1,23 @@
 #!/bin/bash
-# openrefine-batch.sh, Felix Lohmeier, v0.1, 27.02.2017
+# openrefine-batch.sh, Felix Lohmeier, v0.2, 27.02.2017
 # https://github.com/felixlohmeier/openrefine-batch
 
 # user input
 if [ -z "$1" ]
   then
-    echo 1>&2 "please provide path to directory with source files"
+    echo 1>&2 "please provide path to directory with source files (leave empty to transform only)"
     exit 2
   else
     inputdir=$(readlink -f $1)
-    inputfiles=($(basename -a ${inputdir}/*))
+    inputfiles=($(find ${inputdir}/* -type f -printf "%f\n"))
 fi
 if [ -z "$2" ]
   then
-    echo 1>&2 "please provide path to directory with config files"
+    echo 1>&2 "please provide path to directory with config files (leave empty to import only)"
     exit 2
   else
     configdir=$(readlink -f $2)
-    jsonfiles=($(basename -a ${configdir}/*))
+    jsonfiles=($(find ${configdir}/* -type f -printf "%f\n"))
 fi
 if [ -z "$3" ]
   then
@@ -29,31 +29,42 @@ if [ -z "$3" ]
 fi
 if [ -z "$4" ]
   then
-    ram="4G"
+    echo 1>&2 "please provide path to directory with additional OpenRefine projects for use with cross function (may be empty)"
+    exit 2
   else
-    ram="$4"
+    crossdir=$(readlink -f $4)
+    crossprojects=($(find ${crossdir}/* -maxdepth 0 -type d -printf "%f\n"))
 fi
 if [ -z "$5" ]
   then
-    inputformat=""
+    ram="4G"
   else
-    inputformat="--format=${5}"
+    ram="$5"
 fi
 if [ -z "$6" ]
+  then
+    inputformat=""
+  else
+    inputformat="--format=${6}"
+fi
+if [ -z "$7" ]
   then
     inputoptions=""
   else
-    inputoptions=( "$6" "$7" "$8" "$9" "${10}" "${11}" "${12}" "${13}" "${14}" "${15}" )
+    inputoptions=( "$7" "$8" "$9" "${10}" "${11}" "${12}" "${13}" "${14}" "${15}" "${16}" "${17}" "${18}" "${19}" "${20}" )
 fi
 
 # variables
 version="2.7rc1"
 uuid=$(cat /proc/sys/kernel/random/uuid)
-echo "Input dir:              $inputdir"
+echo "Input directory:        $inputdir"
 echo "Input files:            ${inputfiles[@]}"
 echo "Input format:           $inputformat"
 echo "Input options:          ${inputoptions[@]}"
+echo "Config directory:       $configdir"
 echo "Transformation rules:   ${jsonfiles[@]}"
+echo "Cross directory:        $crossdir"
+echo "Cross projects:         ${crossprojects[@]}"
 echo "OpenRefine heap space:  $ram"
 echo "OpenRefine version:     $version"
 echo "Docker container:       $uuid"
@@ -70,37 +81,14 @@ sudo docker run -d --name=${uuid} -v ${outputdir}:/data felixlohmeier/openrefine
 until sudo docker run --rm --link ${uuid} --entrypoint /usr/bin/curl felixlohmeier/openrefine-client --silent -N http://${uuid}:3333 | cat | grep -q -o "OpenRefine" ; do sleep 1; done
 echo ""
 
-# import all files
-for inputfile in "${inputfiles[@]}" ; do
-    echo "import ${inputfile}..."
-    # import
-    sudo docker run --rm --link ${uuid} -v ${inputdir}:/data felixlohmeier/openrefine-client -H ${uuid} -c $inputfile $inputformat ${inputoptions[@]}
-    # show server logs
-    sudo docker attach ${uuid} &
-    # statistics
-    ps -o start,etime,%mem,%cpu,rss -C java
-    # restart server to clear memory
-    echo "save project and restart OpenRefine server..." 
-    sudo docker stop -t=5000 ${uuid}
-    sudo docker rm ${uuid}
-    sudo docker run -d --name=${uuid} -v ${outputdir}:/data felixlohmeier/openrefine:${version} -i 0.0.0.0 -m ${ram} -d /data
-    until sudo docker run --rm --link ${uuid} --entrypoint /usr/bin/curl felixlohmeier/openrefine-client --silent -N http://${uuid}:3333 | cat | grep -q -o "OpenRefine" ; do sleep 1; done
-    echo ""
-done
-
-# get project ids
-projects=($(sudo docker run --rm --link ${uuid} felixlohmeier/openrefine-client -H ${uuid} -l | cut -c 2-14))
-
-# loop for all projects
-for projectid in "${projects[@]}" ; do
-    echo "begin project $projectid @ $(date)"
-    # apply transformation rules
-    for jsonfile in "${jsonfiles[@]}" ; do
-        echo "transform ${jsonfile}..."
+if [ -n "$inputfiles" ]; then
+    # import all files
+    for inputfile in "${inputfiles[@]}" ; do
+        echo "import ${inputfile}..."
+        # import
+        sudo docker run --rm --link ${uuid} -v ${inputdir}:/data felixlohmeier/openrefine-client -H ${uuid} -c $inputfile $inputformat ${inputoptions[@]}
         # show server logs
         sudo docker attach ${uuid} &
-        # apply
-        sudo docker run --rm --link ${uuid} -v ${configdir}:/data felixlohmeier/openrefine-client -H ${uuid} -f ${jsonfile} ${projectid}
         # statistics
         ps -o start,etime,%mem,%cpu,rss -C java
         # restart server to clear memory
@@ -109,38 +97,68 @@ for projectid in "${projects[@]}" ; do
         sudo docker rm ${uuid}
         sudo docker run -d --name=${uuid} -v ${outputdir}:/data felixlohmeier/openrefine:${version} -i 0.0.0.0 -m ${ram} -d /data
         until sudo docker run --rm --link ${uuid} --entrypoint /usr/bin/curl felixlohmeier/openrefine-client --silent -N http://${uuid}:3333 | cat | grep -q -o "OpenRefine" ; do sleep 1; done
+        echo ""
     done
-    # export files
-    echo "export to file ${projectid}.tsv..."
-    # show server logs
-    sudo docker attach ${uuid} &
-    # export
-    sudo docker run --rm --link ${uuid} -v ${outputdir}:/data felixlohmeier/openrefine-client -H ${uuid} -E --output=${projectid}.tsv ${projectid}
-    # statistics
-    ps -o start,etime,%mem,%cpu,rss -C java
-    # restart server to clear memory
-    echo "restart OpenRefine server..." 
-    sudo docker stop -t=5000 ${uuid}
-    sudo docker rm ${uuid}
-    sudo docker run -d --name=${uuid} -v ${outputdir}:/data felixlohmeier/openrefine:${version} -i 0.0.0.0 -m ${ram} -d /data
-    until sudo docker run --rm --link ${uuid} --entrypoint /usr/bin/curl felixlohmeier/openrefine-client --silent -N http://${uuid}:3333 | cat | grep -q -o "OpenRefine" ; do sleep 1; done
-    # time
-    echo "finished project $projectid @ $(date)"
+fi
+
+if [ -n "$jsonfiles" ]; then
+    # get project ids
+    projects=($(sudo docker run --rm --link ${uuid} felixlohmeier/openrefine-client -H ${uuid} -l | cut -c 2-14))
+
+    # copy existing projects for use with OpenRefine cross function
+    if [ -n "$crossprojects" ]; then
+        cp -r $crossdir/*.project $outputdir/
+    fi
+    
+    # loop for all projects
+    for projectid in "${projects[@]}" ; do
+        echo "begin project $projectid @ $(date)"
+        # apply transformation rules
+        for jsonfile in "${jsonfiles[@]}" ; do
+            echo "transform ${jsonfile}..."
+            # show server logs
+            sudo docker attach ${uuid} &
+            # apply
+            sudo docker run --rm --link ${uuid} -v ${configdir}:/data felixlohmeier/openrefine-client -H ${uuid} -f ${jsonfile} ${projectid}
+            # statistics
+            ps -o start,etime,%mem,%cpu,rss -C java
+            # restart server to clear memory
+            echo "save project and restart OpenRefine server..." 
+            sudo docker stop -t=5000 ${uuid}
+            sudo docker rm ${uuid}
+            sudo docker run -d --name=${uuid} -v ${outputdir}:/data felixlohmeier/openrefine:${version} -i 0.0.0.0 -m ${ram} -d /data
+            until sudo docker run --rm --link ${uuid} --entrypoint /usr/bin/curl felixlohmeier/openrefine-client --silent -N http://${uuid}:3333 | cat | grep -q -o "OpenRefine" ; do sleep 1; done
+        done
+        # export files
+        echo "export to file ${projectid}.tsv..."
+        # show server logs
+        sudo docker attach ${uuid} &
+        # export
+        sudo docker run --rm --link ${uuid} -v ${outputdir}:/data felixlohmeier/openrefine-client -H ${uuid} -E --output=${projectid}.tsv ${projectid}
+        # statistics
+        ps -o start,etime,%mem,%cpu,rss -C java
+        # restart server to clear memory
+        echo "restart OpenRefine server..." 
+        sudo docker stop -t=5000 ${uuid}
+        sudo docker rm ${uuid}
+        sudo docker run -d --name=${uuid} -v ${outputdir}:/data felixlohmeier/openrefine:${version} -i 0.0.0.0 -m ${ram} -d /data
+        until sudo docker run --rm --link ${uuid} --entrypoint /usr/bin/curl felixlohmeier/openrefine-client --silent -N http://${uuid}:3333 | cat | grep -q -o "OpenRefine" ; do sleep 1; done
+        # time
+        echo "finished project $projectid @ $(date)"
+        echo ""
+    done
+    # list output files
+    echo "output (number of lines / size in bytes):"
+    wc -c -l ${outputdir}/*.tsv
     echo ""
-done
+fi
 
 # cleanup
 echo "cleanup..."
 sudo docker stop -t=5000 ${uuid}
 sudo docker rm ${uuid}
-sudo rm -r -f ${outputdir}/*.project
 sudo rm -r -f ${outputdir}/workspace*.json
 echo ""
 
-# list output files
-echo "output (number of lines / size in bytes):"
-wc -c -l ${outputdir}/*.tsv
-echo ""
-
 # time
 echo "finish: $(date)"