Name	Info	Provider	Link
	subscription/membership/fee required	Ingenta plc	https://www.ingentaconnect.com/openurl?genre=article&issn=1533-4880&volume=19&issue=1&spage=57&aulast=Liu
Cited by Patents in	free resource	The Lens - Patent Citations	https://www.lens.org/lens/search/patent/list?q=citation_id:30327002