<http://caligraph.org/ontology/April_1850_event>	<http://www.w3.org/2000/01/rdf-schema#subClassOf>	<http://caligraph.org/ontology/April_event> .
<http://caligraph.org/ontology/April_1850_event>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/2002/07/owl#Class> .
<http://caligraph.org/ontology/April_1850_event>	<http://www.w3.org/2000/01/rdf-schema#label>	"April 1850 event" .
<http://caligraph.org/ontology/April_1850_event>	<http://www.w3.org/2000/01/rdf-schema#subClassOf>	<http://caligraph.org/ontology/1850s_event> .
<http://caligraph.org/ontology/April_1850_event>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://en.wikipedia.org/wiki/Category:April_1850_events> .