@article {43, title = {Two new land snails of the Genus Opisthostoma from Borneo (Prosobranchia: Cyclophoracea: Diplommatinidae)}, journal = {Proceedings of the Biological Society of Washington}, volume = {91}, year = {1978}, pages = {386-391}, chapter = {386}, author = {F.G. Thompson} } @article {44, title = {Notes on the non-marine molluscs of the island of Borneo 2. The genus Opisthostoma (Gastropoda Prosobranchia: Diplommatinidae), part 2}, journal = {Basteria}, volume = {55}, year = {1991}, pages = {139-163}, chapter = {139}, author = {J.J. Vermeulen} } @article {35, title = {Notes on the non-marine molluscs of the island of Borneo. 6. The genus Opisthostoma (Gastropoda Prosobranchia: Diplommatinidae), part 2}, journal = {Basteria}, volume = {58}, year = {1994}, pages = {73-191}, chapter = {73}, author = {J.J. Vermeulen} }