About: http://webisa.webdatacommons.org/104880802

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Many good puzzles come from graphs, such as the familiar problem of connecting water, gas, and electricity to three houses without the lines crossing.
http://www.w3.org/ns/prov#wasQuotedFrom	mathematica-journal.com