Sowerby, G. B. II. (1873-1874). Monograph of the genus
Physa. In:
Conchologia iconica, or illustrations of the shells of molluscous animals, vol. 19, pls 1-12 and unpaginated text. L. Reeve, London. [publication dates: pls. 2-7, Feb. 1873; 8-10, Apr. 1873; 1, 11, 12, Nov. 1874].