<http://webisa.webdatacommons.org/269553288>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<google.com> .
<http://webisa.webdatacommons.org/269553288>	<http://www.w3.org/ns/prov#value>	"Second, contaminants such as oil vapors and other organic substances generated, for instance, by vacuum pumps and plastic enclosures tend to form films on optical surfaces causing strong absorption." .
<http://webisa.webdatacommons.org/269553288>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .
<http://webisa.webdatacommons.org/prov/207773477>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/269553288> .