<http://webisa.webdatacommons.org/prov/389621679>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/134091509> .
<http://webisa.webdatacommons.org/134091509>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<ditext.com> .
<http://webisa.webdatacommons.org/134091509>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .
<http://webisa.webdatacommons.org/134091509>	<http://www.w3.org/ns/prov#value>	"Now these intrinsic peculiarities can hardly be expressed and treated in detail except by introducing some system of co-ordinates for the points of the surface under consideration." .