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.
naturalis.nl
repository.naturalis.nl
Wesselingh F. P. (2006). "Molluscs from the Miocene Pebas Formation of Peruvian and Colombian Amazonia". Scripta Geologica133: 19-290. Figure 274.
abstract, PDF