@book {768,
	title = {Manual of Conchology : structural and systematic, with illustrations of the species : second Series: Pulmonata},
	volume = {13},
	number = {2},
	year = {1900},
	pages = {254},
	address = {Philadelphia},
	url = {http://www.biodiversitylibrary.org/item/76174$\#$9},
	author = {G.W. Tryon},
	editor = {H.A. Pilsbry}
}
@book {768,
	title = {Manual of Conchology : structural and systematic, with illustrations of the species : second Series: Pulmonata},
	volume = {25},
	number = {2},
	year = {1918},
	pages = {433},
	address = {Philadelphia},
	url = {http://www.biodiversitylibrary.org/item/76602$\#$page/418/mode/1up},
	author = {G.W. Tryon},
	editor = {H.A. Pilsbry}
}
