diff --git a/sru/onbsru.py b/sru/onbsru.py
index e5935e87af8dff0f426e9bbfe9ce3d285f22a8f5..4f31370002e7e1ca7424792a081e7144f42ba973 100644
--- a/sru/onbsru.py
+++ b/sru/onbsru.py
@@ -6,8 +6,6 @@ from . import almasru
 
 
 class OnbRecordRetriever(almasru.RecordRetriever):
-    dtl_re = re.compile(r'dtl\/\d*')
-    pid_re = re.compile(r'\d+')
 
     def __init__(self,
                  subdomain: str = 'obv-at-oenb',
@@ -21,6 +19,9 @@ class OnbRecordRetriever(almasru.RecordRetriever):
             'marc': 'http://www.loc.gov/MARC21/slim'
         }
 
+        self.dtl_re = re.compile(r'dtl\/\d*')
+        self.pid_re = re.compile(r'\d+')
+
     # Create alias for querying AC-numbers
     def by_ac_num(self, ac_num: str):
         return self.by_marc_009(ac_num)
@@ -41,16 +42,12 @@ class OnbRecordRetriever(almasru.RecordRetriever):
         for datafield in datafields:
             if datafield.attrib == {'tag': '856', 'ind1': '4', 'ind2': '2'}:
 
-                marc_856_u = self._get_subfield(datafield, 'u')
-                marc_856_url = marc_856_u.text
-
-                marc_856_x = self._get_subfield(datafield, 'x')
-                marc_856_note = marc_856_x.text
+                marc_856_url = self._get_subfield(datafield, 'u').text
+                marc_856_note = self._get_subfield(datafield, 'x').text
 
                 if 'ONB-DTL' in marc_856_note:
                     dtl_suffix = self.dtl_re.findall(marc_856_url)[0]
-                    print(dtl_suffix)
-                    pids.append(self.pid_re.findall(dtl_suffix))
+                    pids.append(self.pid_re.findall(dtl_suffix)[-1])
 
         return pids