+<filter xmlns="http://indexdata.com/metaproxy" type="sparql">
+ <db path="Default" uri="http://bibframe.indexdata.com/sparql/">
+ <prefix>rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns</prefix>
+ <prefix>bf: http://bibframe.org/vocab/</prefix>
+ <field>?work ?wtitle</field>
+ <criteria>?work a bf:Work</criteria>
+ <criteria>?work bf:workTitle ?wt</criteria>
+ <criteria>?wt bf:titleValue ?wtitle</criteria>
+ <index type="bf.wtitle">?wt bf:titleValue %v FILTER(contains(%v, %s))</index>
+ </db>
+</filter>