Shmidt, O. I. 1984. Chapter II. Sea urchins. Pp. 147-150 in Menner, V. V. (ed.) Atlas of fauna and flora of the Neogene sediments of the Far East. Tochilinski key section of western Kamchatka. Trudy Geologicheskogo Instituta Akademiya Nauk SSSR 385, 147-150.