E. A.  Smith, ?On a collection of land-shells from Sarawak, British North Borneo, Palawan, and other neighbouring islands?, Proceedings of the Zoological Society of London, vol. 1895, pp. 97?127, 1895.

E. A.  Smith, ?On the land-shells of the Sulu Archipelago?, The annals and magazine of natural history, including zoology, botany and geology, vol. 13, pp. 48-60, 1894.