diff --git a/ortsregister.odd b/ortsregister.odd
index 46aa0f06f12212efb2066f75e73b2633ae6f187d..fb73e7aace3c55d0ed48757945c9b78c5dc48f2b 100644
--- a/ortsregister.odd
+++ b/ortsregister.odd
@@ -568,7 +568,32 @@
                                 <rng:data type="anyURI"/>
                             </datatype>
                             <constraintSpec scheme="schematron" ident="ptr-regex">
-                                <constraint> <sch:pattern> <sch:rule context="tei:ptr[not(./@type)]"> <sch:let name="variable" value="substring(./@target,5)"/> <sch:assert test="(document('../Register/bibliography.xml')//*[@xml:id eq $variable])">ID "<sch:value-of select="$variable"/>" ist in der Bibliographie nicht vorhanden.</sch:assert> </sch:rule> </sch:pattern> </constraint>
+                                <constraint> <sch:pattern> <sch:rule context="tei:ptr[not(./@type)]"> <sch:let name="variable" value="substring(./@target,5)"/> <sch:assert test="$variable ne '' and
+                                    (
+                                    document('../Register/bibliography/bibliography-a.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-b.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-c.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-d.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-e.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-f.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-g.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-h.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-i.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-j.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-k.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-l.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-m.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-n.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-o.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-p.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-qr.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-s.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-t.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-u.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-v.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-w.xml')//*[@xml:id eq $variable] or
+                                    document('../Register/bibliography/bibliography-xyz.xml')//*[@xml:id eq $variable]
+                                    )">ID "<sch:value-of select="$variable"/>" ist in der Bibliographie nicht vorhanden.</sch:assert> </sch:rule> </sch:pattern> </constraint>
                             </constraintSpec>
                         </attDef>
                     </attList>
@@ -598,7 +623,32 @@
                                 <rng:data type="anyURI"/>
                             </datatype>
                             <constraintSpec scheme="schematron" ident="ref-regex">
-                                <constraint> <sch:pattern> <sch:rule context="tei:bibl/tei:ref"> <sch:let name="variable1" value="substring(./@target,5)"/> <sch:let name="variable2" value="substring(./@target,1,3)"/> <sch:assert test="(document('../Register/bibliography.xml')//*[@xml:id eq $variable1] and $variable2 eq 'lit')">ID "<sch:value-of select="$variable1"/>" ist in der Literaturverzeichnisdatei nicht vorhanden.</sch:assert> </sch:rule> </sch:pattern> </constraint>
+                                <constraint> <sch:pattern> <sch:rule context="tei:bibl/tei:ref"> <sch:let name="variable1" value="substring(./@target,5)"/> <sch:let name="variable2" value="substring(./@target,1,3)"/> <sch:assert test="($variable1 ne '' and
+                                    (
+                                    document('../Register/bibliography/bibliography-a.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-b.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-c.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-d.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-e.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-f.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-g.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-h.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-i.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-j.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-k.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-l.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-m.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-n.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-o.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-p.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-qr.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-s.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-t.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-u.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-v.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-w.xml')//*[@xml:id eq $variable1] or
+                                    document('../Register/bibliography/bibliography-xyz.xml')//*[@xml:id eq $variable1]
+                                    ) and $variable2 eq 'lit')">ID "<sch:value-of select="$variable1"/>" ist in keiner Literaturverzeichnisdatei vorhanden.</sch:assert> </sch:rule> </sch:pattern> </constraint>
                                 </constraintSpec>
                         </attDef>
                     </attList>
@@ -740,7 +790,32 @@ and $variable2 eq 'wrk'
 
 )
 
-or (document('../Register/bibliography.xml')//*[@xml:id eq $variable1] and $variable2 eq 'lit')">ID ist in der angegebenen Registerdatei nicht vorhanden.</sch:assert> </sch:rule> </sch:pattern> </constraint>
+or ($variable1 ne '' and
+(
+document('../Register/bibliography/bibliography-a.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-b.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-c.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-d.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-e.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-f.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-g.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-h.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-i.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-j.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-k.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-l.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-m.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-n.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-o.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-p.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-qr.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-s.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-t.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-u.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-v.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-w.xml')//*[@xml:id eq $variable1] or
+document('../Register/bibliography/bibliography-xyz.xml')//*[@xml:id eq $variable1]
+) and $variable2 eq 'lit')">ID ist in der angegebenen Registerdatei nicht vorhanden.</sch:assert> </sch:rule> </sch:pattern> </constraint>
                             </constraintSpec>
                         </attDef>
                         <attDef ident="type" usage="req">