H. H.  Godwin-Austen, ?On a Collection of Land-Shells made in Borneo by Mr. A. Everett, with Descriptions of supposed new Species. Part II. Zonitidae and Helicidae.?, Proceedings of the Zoological Society of London, pp. 22-47, 1891.

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.