De Kock, K. and Wolmarans, C. 2006. Distribution and habitats of Gyraulus costulatus, potential snail intermediate host of intestinal flukes of the family Echinostomatidae in South Africa. Suid-Afrikaans Tydskrif vir Natuurwetenskap en Tegnologie / <i>South African Journal of Science and Technology</i&gt;. 25, 1 (Sep. 2006), 19-31. DOI:https://doi.org/10.4102/satnt.v25i1.141.