@unpublished {542,
	title = {The Mollusca collected by the University of Michigan-Williamson expedition in Venezuela},
	year = {1930},
	pages = {210: 1-95},
	author = {Baker, H.B.}
}
@unpublished {540,
	title = {The Mollusca collected by the University of Michigan-Walker expedition in southern Vera Cruz, Mexico},
	year = {1922},
	pages = {106: 1-95},
	author = {Baker, H.B.}
}
@article {541,
	title = {Type land snails in the Academy of Natural Sciences of Philadelphia. Part III. Limnophile and thalassophile Pulmonata. Part IV. Land and fresh-water Prosobranchia},
	journal = {Proceedings of the Academy of Natural Sciences of Philadelphia},
	volume = {116},
	year = {1964},
	pages = {149-193},
	author = {Baker, H.B.}
}
