@article {385,
	title = {Shell variation in sympatric Lymnaea pergera and L. ovata (Gastropoda: Lymnaeidae)},
	journal = {Biological Journal of Linnean Society},
	volume = {61},
	year = {1997},
	pages = {139-149},
	author = {Ward, PI and Goater, CP and Mikos, M}
}
