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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	The sheet covering can be made of any suitable material, such as reinforced plastic, canvas or other material, that is tough, durable and impervious to water.
http://www.w3.org/ns/prov#wasQuotedFrom	freepatentsonline.com