Interpopulation Variation in Sex Ratio of the Japanese Pond Turtle Mauremys japonica (Reptilia: Geoemydidae) Okada, Yuki and Yabe, Takashi and Oda, Sen-Ichi, Current Herpetology, 30, 53-61 (2011), DOI:http://dx.doi.org/10.3105/018.030.0105