@prefix skos:	<http://www.w3.org/2004/02/skos/core#> .
@prefix isac:	<http://webisa.webdatacommons.org/concept/> .
isac:_oscillator_	skos:broader	isac:frequency_source_ .
isac:_crystal_	skos:broader	isac:frequency_source_ .
isac:crystal_oscillator_	skos:broader	isac:frequency_source_ .
isac:frequency_synthesizer_	skos:broader	isac:frequency_source_ .