Moser, W. E., S. V. Fend, D. J. Richardson, C. I. Hammond, E. A. Lazo-Wasem, F. R. Govedich, and B. S. Gullo. “A New Species of Helobdella (Hirudinida: Glossiphoniidae) from Oregon, USA”. Zootaxa, vol. 3718, no. 3, Oct. 2013, pp. 287–294, doi:10.11646/zootaxa.3718.3.5.