Bullen, R.A. 1906. On some land and fresh-water Mollusca from Sumatra. Proceedings of the Malacological Society of London 7: 12-. Available electronically.

Bullen, 1906. Proc. Malac. Soc. London 7: 15, pl. 2, figs. 9-11.
Type(s): HOLOTYPE BMNH_1906-1-16-52, Pajakombo, Sumatra.
Unio pajakomboensis n. sp. = Lens contradens