AKAMATSU, M. Stratigraphy and paleoenvironment of the lower Pleistocene on the hills around the Ishikari Lowland, Hokkaido. Ann. Rep. Hist. Mus. Hokkaido. 1992, 20, 1-30
BABA, K. Molluscan fossil assemblages of the Kazusa Group, South Kwanto, central Japan. 1990, 445
CHINZEI, K. Molluscan fauna of the Pliocene Sannohe Group of Northeast Honshu, Japan. 1. The faunule of the Kubo Formation. Jour. Fac. Sci., Univ. Tokyo, Sec. 2. 1959, 12, pt. 1, 103-132
HABE, T. Coloured illustrations of the shells of Japan. 1961, II, 182, 66 pls