Yamazaki, K., Yamazaki, M. & Ueshima, R. (2013)

Systematic review of diplommatinid land snails (Caenogastropoda, Diplommatinidae) endemic to the Palau Islands. (1) Generic classification and revision of Hungerfordia
species with highly developed axial ribs

. Zootaxa, 3743 (1), 1–71.