<http://caligraph.org/ontology/20th-century_natural_event>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://en.wikipedia.org/wiki/Category:20th-century_natural_events> .
<http://caligraph.org/ontology/20th-century_solar_eclipse>	<http://www.w3.org/2000/01/rdf-schema#subClassOf>	<http://caligraph.org/ontology/20th-century_natural_event> .
<http://caligraph.org/ontology/20th-century_natural_event>	<http://www.w3.org/2000/01/rdf-schema#label>	"20th-century natural event" .
<http://caligraph.org/ontology/20th-century_lunar_eclipse>	<http://www.w3.org/2000/01/rdf-schema#subClassOf>	<http://caligraph.org/ontology/20th-century_natural_event> .
<http://caligraph.org/ontology/20th-century_natural_event>	<http://www.w3.org/2000/01/rdf-schema#subClassOf>	<http://caligraph.org/ontology/2nd-millennium_natural_event> .
<http://caligraph.org/ontology/20th-century_natural_event>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/2002/07/owl#Class> .
<http://caligraph.org/ontology/20th-century_volcanic_event>	<http://www.w3.org/2000/01/rdf-schema#subClassOf>	<http://caligraph.org/ontology/20th-century_natural_event> .