diff --git a/isbn/alma-sru.php b/isbn/alma-sru.php
index 06a77f4..9c53582 100644
--- a/isbn/alma-sru.php
+++ b/isbn/alma-sru.php
@@ -28,9 +28,9 @@
 include 'conf.php';
 include 'lib.php';
 
-if (isset($_GET['bibliothek'])) {
-    $file = file_get_contents('./srulibraries.json');
-    $json = json_decode($file, true);
+$file = file_get_contents('./srulibraries.json');
+$json = json_decode($file, true);
+if (isset($_GET['bibliothek']) and isset($json[$_GET['bibliothek']])) {
     $urlBase = $json[$_GET['bibliothek']]['sru'];
 } else {
     echo "Bibliothek nicht gefunden in der Liste der bekannten Alma-SRU-Schnittstellen.\n";
@@ -118,9 +118,16 @@
                     // Delete check value at the end for ISBN10
                     $testString = substr($testString, 0, -1);
                 }
-            }
-            if (strpos($foundValue, $testString) !== false) {
-                $foundMatch = true;
+                // for isbn, check that the test string is part of the found value
+                if (strpos($foundValue, $testString) !== false) {
+                    $foundMatch = true;
+                }
+            } else {
+                // for ppn (or other ids), skip the possible prefix in paranthesis and then they need to be exactly the same
+                $foundValue = preg_replace('/^\(.*\)/', '', $foundValue);
+                if ($foundValue == $testString) {
+                    $foundMatch = true;
+                }
             }
         }
     }
@@ -187,9 +194,6 @@
 
             $location = getValues($node->xpath('./subfield[@code="b"]')[0]);
             $sublocation = getValues($node->xpath('./subfield[@code="c"]')[0]);
-            /*if (strpos($sublocation, "Lehrbuchsammlung") !== false) {
-                $location = "LBS";
-            }*/
 
             $node_f = $node->xpath('./subfield[@code="f"]');
             $number = count($node_f) ? getValues($node_f[0]) : 0;
diff --git a/isbn/dnb.php b/isbn/dnb.php
index 0d6ce5e..57d1cf8 100644
--- a/isbn/dnb.php
+++ b/isbn/dnb.php
@@ -20,16 +20,8 @@
  * Sucht übergebene ISBN bzw. PPN in der SRU-Schnittstelle der DNB
  * und gibt maximal 10 Ergebnisse als MARCXML oder JSON zurück.
  */
-
-include 'conf.php';
-include 'lib.php';
-
-if (isset($_GET['ppn'])) {
-    $ppn = trim($_GET['ppn']);
-    $suchString = 'dnb.idn=' . $ppn;
-}
-
-/*
+ 
+ /*
 Explain SRU
 
 https://services.dnb.de/sru/dnb?version=1.1&operation=explain
@@ -40,12 +32,19 @@
 
 */
 
+include 'conf.php';
+include 'lib.php';
+
+if (isset($_GET['ppn'])) {
+    $ppn = trim($_GET['ppn']);
+    $suchString = 'dnb.idn=' . $ppn;
+}
+
 $urlBase = 'https://services.dnb.de/sru/dnb?version=1.1&operation=searchRetrieve&recordSchema=MARC21-xml&query=';
 if (isset($_GET['isbn'])) {
     $n = trim($_GET['isbn']);
     $nArray = preg_split("/\s*(or|,|;)\s*/i", $n, -1, PREG_SPLIT_NO_EMPTY);
     $suchString = 'dnb.num=' . implode('+OR+dnb.num=', $nArray);
-    $suchStringSWB = implode(' or ', $nArray);
 }
 
 $result = file_get_contents($urlBase . $suchString, false);
@@ -75,29 +74,8 @@
 
 
 foreach ($records as $record) {
-    // Filter out any other results which contain the ISBN but not in the 020 or 776 field
-    $foundMatch = false;
-    $foundIsbns = $xpath->query('.//datafield[@tag="020" or @tag="776"]/subfield', $record);
-    foreach ($foundIsbns as $foundNode) {
-        $foundValue = $foundNode->nodeValue;
-        foreach ($nArray as $queryValue) {
-            $testString = preg_replace('/[^0-9xX]/', '', $queryValue);
-            if (strlen($testString) == 13) {
-                // Delete the 978-prefix and the check value at the end for ISBN13
-                $testString = substr($testString, 3, -1);
-            } elseif (strlen($testString) == 10) {
-                // Delete check value at the end for ISBN10
-                $testString = substr($testString, 0, -1);
-            }
-            if (strpos(preg_replace('[^0-9xX]', '', $foundValue), $testString) !== false) {
-                $foundMatch = true;
-            }
-        }
-    }
-    if ($foundMatch) {
-        $outputString .= $doc->saveXML($record);
-        array_push($outputArray, $doc->saveXML($record));
-    }
+    $outputString .= $doc->saveXML($record);
+    array_push($outputArray, $doc->saveXML($record));
 }
 $outputString .= "</collection>";
 
diff --git a/isbn/suche.html b/isbn/suche.html
index 3f2b842..2ae1661 100644
--- a/isbn/suche.html
+++ b/isbn/suche.html
@@ -30,7 +30,7 @@
     alert("jQuery wurde nicht gefunden");
 }
 </script>
-<script src="rendering.js"></script>
+<script src="rendering.js?20250104"></script>
 <script src="paketinfo.js"></script>
 <script type="text/javascript">
 function toggleHidden() {
@@ -226,6 +226,7 @@
     });
 
     var meinVerbund = getParameterByName("verbund").toLowerCase() || "k10plus";
+    document.querySelector("#selectPpn").value = meinVerbund;
     //Damit werden die Variablen ueber HTML ausgewertet (so wie GET Variablen in PHP)
     if (getParameterByName("isbn")) {
         $('#eingabeIsbn').val(getParameterByName("isbn"));
@@ -234,7 +235,6 @@
     } else if (getParameterByName("ppn")) {
         $('#eingabePpn').val(getParameterByName("ppn"));
         $('#eingabeIsbn').val('');
-        document.querySelector("#formPpn select").value = meinVerbund;
         ppnEingabe(getParameterByName("ppn"), meinVerbund);
     }
     
@@ -361,11 +361,11 @@
     }
     // Bestandsabgleich durchführen
     $.get(url, function(data){
-        var holdingsMAN = pattern.exec(data);
-        if (holdingsMAN) {
+        var holdings = pattern.exec(data);
+        if (holdings) {
              var detailsLink = $('<a/>').attr('href', url).attr('onclick', 'return toggleHidden()').text("Details");
              var bestandsLine = $('<div/>').attr('style', "background-color:#ffbbbb")
-               .text(label + holdingsMAN[1]+ ' (')
+               .text(label + holdings[1]+ ' (')
                .append(detailsLink)
                .append(')<div id="detailsText" style="display: none;" class="hidden"><br/></div>');
              $('#bestandsabgleich').append('<br/>').append(bestandsLine);
@@ -493,7 +493,7 @@ <h1>Unterstützungstool für Fachreferatsarbeit</h1>
         <td id="idTD">
             <form id="formPpn" name='formular'  action="#">&nbsp; &nbsp; &nbsp;
                 <input id="eingabePpn" type="search" size="20" maxlength="30" placeholder="id...">
-                <select>
+                <select id="selectPpn">
                     <option type="radio" name="eingabeVerbund" value="k10plus">k10plus
                     <option type="radio" name="eingabeVerbund" value="swb">swb
                     <option type="radio" name="eingabeVerbund" value="b3kat">b3kat