<http://webisa.webdatacommons.org/prov/469112338>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/402297323> .
<http://webisa.webdatacommons.org/402297323>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .
<http://webisa.webdatacommons.org/402297323>	<http://www.w3.org/ns/prov#value>	"In the case of highly attenuating fluids, such as drilling mud, then a low frequency collimated sound source is used.2011-04-28" .
<http://webisa.webdatacommons.org/402297323>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<faqs.org> .