Turton W. (1831). A manual of the land and freshwater shells of the British Islands. 152 pp., 9, plates. Longman, Rees, Orme, Brown & Greene, London.8: 97. (original spelling: Pupilladae.)
Barker G. M.: Gastropods on Land: Phylogeny, Diversity and Adaptive Morphology. in Barker G. M. (ed.): The biology of terrestrial molluscs. CABI Publishing, Oxon, UK, 2001, ISBN0-85199-318-4. 1-146, cited pages: 139 and 142.
