Hyolithida of the Amur part of the Middle Cambrian of the north west Siberian platform; In Stratigraphy and Palaeontology of the Proterozoic and Cambrian of the Siberian platform. Akad. Nauk SSSR, Yakutsk. Filial, Sibirsk. Otdel.; Inst. Geol., Yakutsk.: 8