Pilsbry, H. A. (1890-1891).
Manual of conchology, structural and systematic, with illustrations of the species. Ser. 2, Pulmonata. Vol. 6: Helicidae, vol. 4. pp 1-324, pls 1-69. Philadelphia, published by the Conchological Section, Academy of Natural Sciences. [pp. 1-64, pls 1-15, 27 May 1890; pp. 65-128, pls 16-30, 12 Aug 1890; pp. 129-192, pls 31-47, 16 Dec 1890; pp. 193-324, pls 48-69, 19 May 1891].