<http://caligraph.org/ontology/Rocket_engine_using_hydrogen_propellant>	<http://www.w3.org/2000/01/rdf-schema#label>	"Rocket engine using hydrogen propellant" .
<http://caligraph.org/ontology/Rocket_engine_using_hydrogen_propellant>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://en.wikipedia.org/wiki/Category:Rocket_engines_using_hydrogen_propellant> .
<http://caligraph.org/ontology/Rocket_engine_using_hydrogen_propellant>	<http://www.w3.org/2000/01/rdf-schema#subClassOf>	<http://caligraph.org/ontology/Rocket_engine> .
<http://caligraph.org/ontology/Rocket_engine_using_hydrogen_propellant>	<http://www.w3.org/2000/01/rdf-schema#subClassOf>	<http://caligraph.org/ontology/Hydrogen_technology> .
<http://caligraph.org/ontology/Rocket_engine_using_hydrogen_propellant>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/2002/07/owl#Class> .