Biostratigraphic significance of new fossil species of the diatom genera Stephanodiscus and Cyclotella from upper Cenozoic deposits of Lake Baikal, Siberia Alexander A. Prokopenko, Douglas F. Williams, Eugene B. Karabanov, Galina K. Khursevich, Mikhail I. Kuzmin, and Svetlana A. Fedenya. Micropaleontology Volume 47, No. 1 pp. 47-71