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 Natuna Islands?, The annals and magazine of natural history, including zoology, botany and geology, vol. 6, pp. 453-463, 1894.

E.  von Martens, ?Beschreibung einiger im östlichen Borneo von Dr. Martin Schmidt gesammelten Land und Süßwasser-Conchylien.?, Mitteilungen aus dem Zoologischen Museum, vol. 4, pp. 251-291, 1908.