Field study on the habitat of nautilus in the environs of Cebu and Negros Islands, the Philippines - Hayasaka, Shozo; Saisho, Toshio; Kakinuma, Yoshiko; Shinomiya, Akihiku; Oki, Kimihiko; Hamada, Takashi; Tanabe, Kazushige; Kanie, Yasumitsu; Hattori, Mutsuo; Vusse, Frederick Vande; Alcala, Lawton; Cordero, Paciente A., Jr; et al.