H. Yamasaki, H. Kajihara, and S. F. Mawatari, “First report of kinorhynchs from Hokkaido, Japan, including a new species of Pycnophyes (Pycnophyidae: Homalorhagida)”, Zootaxa, vol. 3425, no. 1, pp. 23–41, Aug. 2012.