S. Katoh, S. Nagaoka, G. WoldeGabriel, P. Renne, M. G. Snow, Y. Beyene, and G. Suwa. Chronostratigraphy and correlation of the {Plio-Pleistocene} tephra layers of the Konso Formation, southern Main Ethiopian Rift, Ethiopia. Quaternary Science Reviews, volume 19, issue 13, pages 1305-1317, 2000.

G. Suwa, B. Asfaw, Y. Beyene, T. D. White, S. Katoh, S. Nagaoka, H. Nakaya\&num, K. Uzawa, P. Renne, and G. WoldeGabriel. The first skull of Australopithecus boisei. Nature, volume 389, issue 6650, pages 489-492, 1997.