About: http://webisa.webdatacommons.org/331907261

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	Such a structure can be formed e.g. by means of forwardly convergent or oblique or roundly formed annular surfaces which reflect to the sound inwardly.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com