<http://webisa.webdatacommons.org/prov/276611044>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/231625513> .
<http://webisa.webdatacommons.org/231625513>	<http://www.w3.org/ns/prov#value>	"Other factors, such as refusal to be interviewed and weighting, may introduce additional error that is more difficult to quantify.http://www.publicpolicypolling.com/pdf/PPP_Release_PA_420.pdf" .
<http://webisa.webdatacommons.org/231625513>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .
<http://webisa.webdatacommons.org/231625513>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<uselectionatlas.org> .