diff --git a/app/Http/Controllers/Oai/RequestController.php b/app/Http/Controllers/Oai/RequestController.php
index b30de8f..36ad97a 100644
--- a/app/Http/Controllers/Oai/RequestController.php
+++ b/app/Http/Controllers/Oai/RequestController.php
@@ -26,7 +26,7 @@ class RequestController extends Controller
      */
     private $deliveringDocumentStates = array('published', 'deleted'); // maybe deleted documents too
     //private $xMetaDissRestriction = array('doctoralthesis', 'habilitation');
-    const SET_SPEC_PATTERN = '[A-Za-z0-9\-_\.!~\*\'\(\)]+';
+    const SET_SPEC_PATTERN = '[A-Za-zäöüÄÖÜß0-9\-_\.!~\*\'\(\)]+';
 
     /**
      * Holds xml representation of document information to be processed.
@@ -323,6 +323,7 @@ class RequestController extends Controller
 
         //$oaiSets = new Oai_Model_Sets();
         $sets = array(
+            'open_access' => 'Set for open access licenses',
             // 'bibliography:true' => 'Set for bibliographic entries',
             // 'bibliography:false' => 'Set for non-bibliographic entries',
         );
@@ -435,6 +436,13 @@ class RequestController extends Controller
                             $q->where('label', $setarray[1]);
                         });
                     }
+                } elseif (!empty($setarray[0]) && $setarray[0] == 'open_access') {                   
+                    $openAccessLicences = ["CC-BY-4.0", "CC-BY-SA-4.0"];
+                    $finder->whereHas('licenses', function ($q) use ($openAccessLicences) {
+                        $q->whereIn('name', $openAccessLicences);
+                        // $q->where('name', '=', "CC-BY-4.0")->orWhere('name', '=',"CC-BY-SA-4.0");
+                    });
+                    //$test = $finder->toSql();
                 }
             }
 
@@ -455,7 +463,7 @@ class RequestController extends Controller
                 }
                 $finder->where('server_date_published', '>=', $fromDate)
                     ->where('server_date_published', '<=', $untilDate);
-                $test = $finder->toSql();
+                // $test = $finder->toSql();
             } elseif (array_key_exists('until', $oaiRequest) && !array_key_exists('from', $oaiRequest)) {
                 $until = $oaiRequest['until'];
                 try {
@@ -467,7 +475,8 @@ class RequestController extends Controller
                     $earliestPublicationDate = Dataset::earliestPublicationDate()->server_date_published;
                     if ($earliestPublicationDate->gt($untilDate)) {
                         throw new OaiModelException(
-                            "earliestDatestamp is greater than given until date. The given values results in an empty list.",
+                            "earliestDatestamp is greater than given until date.
+                            The given values results in an empty list.",
                             OaiModelError::NORECORDSMATCH
                         );
                     } else {
@@ -476,7 +485,8 @@ class RequestController extends Controller
                     }
                 } catch (OaiModelException $e) {
                     throw new OaiModelException(
-                        "earliestDatestamp is greater than given until date. The given values results in an empty list.",
+                        "earliestDatestamp is greater than given until date.
+                        The given values results in an empty list.",
                         OaiModelError::NORECORDSMATCH
                     );
                 } catch (\Exception $e) {
diff --git a/composer.lock b/composer.lock
index cebd1b3..5ac6bc0 100755
--- a/composer.lock
+++ b/composer.lock
@@ -2282,16 +2282,16 @@
         },
         {
             "name": "nesbot/carbon",
-            "version": "2.55.2",
+            "version": "2.56.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/briannesbitt/Carbon.git",
-                "reference": "8c2a18ce3e67c34efc1b29f64fe61304368259a2"
+                "reference": "626ec8cbb724cd3c3400c3ed8f730545b744e3f4"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/briannesbitt/Carbon/zipball/8c2a18ce3e67c34efc1b29f64fe61304368259a2",
-                "reference": "8c2a18ce3e67c34efc1b29f64fe61304368259a2",
+                "url": "https://api.github.com/repos/briannesbitt/Carbon/zipball/626ec8cbb724cd3c3400c3ed8f730545b744e3f4",
+                "reference": "626ec8cbb724cd3c3400c3ed8f730545b744e3f4",
                 "shasum": ""
             },
             "require": {
@@ -2308,7 +2308,7 @@
                 "kylekatarnls/multi-tester": "^2.0",
                 "phpmd/phpmd": "^2.9",
                 "phpstan/extension-installer": "^1.0",
-                "phpstan/phpstan": "^0.12.54",
+                "phpstan/phpstan": "^0.12.54 || ^1.0",
                 "phpunit/phpunit": "^7.5.20 || ^8.5.14",
                 "squizlabs/php_codesniffer": "^3.4"
             },
@@ -2374,7 +2374,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2021-12-03T14:59:52+00:00"
+            "time": "2022-01-21T17:08:38+00:00"
         },
         {
             "name": "nikic/php-parser",
@@ -3225,16 +3225,16 @@
         },
         {
             "name": "solarium/solarium",
-            "version": "6.2.1",
+            "version": "6.2.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/solariumphp/solarium.git",
-                "reference": "3c13804d3e12b2783ca450a4e8a6d759e496d651"
+                "reference": "0f5c81eee5529556f349eaacfbf5ce3cfbb2be47"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/solariumphp/solarium/zipball/3c13804d3e12b2783ca450a4e8a6d759e496d651",
-                "reference": "3c13804d3e12b2783ca450a4e8a6d759e496d651",
+                "url": "https://api.github.com/repos/solariumphp/solarium/zipball/0f5c81eee5529556f349eaacfbf5ce3cfbb2be47",
+                "reference": "0f5c81eee5529556f349eaacfbf5ce3cfbb2be47",
                 "shasum": ""
             },
             "require": {
@@ -3282,9 +3282,9 @@
             ],
             "support": {
                 "issues": "https://github.com/solariumphp/solarium/issues",
-                "source": "https://github.com/solariumphp/solarium/tree/6.2.1"
+                "source": "https://github.com/solariumphp/solarium/tree/6.2.2"
             },
-            "time": "2021-12-26T10:15:52+00:00"
+            "time": "2022-01-20T17:45:10+00:00"
         },
         {
             "name": "swiftmailer/swiftmailer",
@@ -5695,16 +5695,16 @@
         },
         {
             "name": "voku/portable-ascii",
-            "version": "1.5.6",
+            "version": "1.6.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/voku/portable-ascii.git",
-                "reference": "80953678b19901e5165c56752d087fc11526017c"
+                "reference": "87337c91b9dfacee02452244ee14ab3c43bc485a"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/voku/portable-ascii/zipball/80953678b19901e5165c56752d087fc11526017c",
-                "reference": "80953678b19901e5165c56752d087fc11526017c",
+                "url": "https://api.github.com/repos/voku/portable-ascii/zipball/87337c91b9dfacee02452244ee14ab3c43bc485a",
+                "reference": "87337c91b9dfacee02452244ee14ab3c43bc485a",
                 "shasum": ""
             },
             "require": {
@@ -5741,7 +5741,7 @@
             ],
             "support": {
                 "issues": "https://github.com/voku/portable-ascii/issues",
-                "source": "https://github.com/voku/portable-ascii/tree/1.5.6"
+                "source": "https://github.com/voku/portable-ascii/tree/1.6.1"
             },
             "funding": [
                 {
@@ -5765,7 +5765,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2020-11-12T00:07:28+00:00"
+            "time": "2022-01-24T18:55:24+00:00"
         },
         {
             "name": "yajra/laravel-datatables-oracle",
@@ -6636,16 +6636,16 @@
         },
         {
             "name": "phpunit/phpunit",
-            "version": "9.5.11",
+            "version": "9.5.13",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/phpunit.git",
-                "reference": "2406855036db1102126125537adb1406f7242fdd"
+                "reference": "597cb647654ede35e43b137926dfdfef0fb11743"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/2406855036db1102126125537adb1406f7242fdd",
-                "reference": "2406855036db1102126125537adb1406f7242fdd",
+                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/597cb647654ede35e43b137926dfdfef0fb11743",
+                "reference": "597cb647654ede35e43b137926dfdfef0fb11743",
                 "shasum": ""
             },
             "require": {
@@ -6723,7 +6723,7 @@
             ],
             "support": {
                 "issues": "https://github.com/sebastianbergmann/phpunit/issues",
-                "source": "https://github.com/sebastianbergmann/phpunit/tree/9.5.11"
+                "source": "https://github.com/sebastianbergmann/phpunit/tree/9.5.13"
             },
             "funding": [
                 {
@@ -6735,7 +6735,7 @@
                     "type": "github"
                 }
             ],
-            "time": "2021-12-25T07:07:57+00:00"
+            "time": "2022-01-24T07:33:35+00:00"
         },
         {
             "name": "sebastian/cli-parser",
diff --git a/public/datasetxml2oai-pmh.xslt b/public/datasetxml2oai-pmh.xslt
index 1dc1f8c..68bcba1 100644
--- a/public/datasetxml2oai-pmh.xslt
+++ b/public/datasetxml2oai-pmh.xslt
@@ -564,12 +564,12 @@
     </dc:format>
   </xsl:template>
 
-  <xsl:template match="File" mode="oai_dc">
+  <!--  <xsl:template match="File" mode="oai_dc">
     <dc:identifier>
-      <!-- <xsl:value-of select="@PathName" /> -->      
+     <xsl:value-of select="@PathName" />        
       <xsl:value-of select="concat($downloadLink, @Id)" />
     </dc:identifier>
-  </xsl:template>
+  </xsl:template> -->
 
    <xsl:template match="Identifier" mode="oai_dc">
          <dc:identifier>