S. W. Simpson, N. E. Levin, J. Quade, M. J. Rogers, and S. Semaw. Ardipithecus ramidus postcrania from the Gona Project area, Afar Regional State, Ethiopia. J. Hum. Evol., volume 129, pages 1-45, April 2019.

Y. Haile-Selassie, L. Gibert, S. M. Melillo, T. M. Ryan, M. Alene, A. Deino, N. E. Levin, G. Scott, and B. Z. Saylor. New species from Ethiopia further expands Middle Pliocene hominin diversity. Nature, nature.com, volume 521, issue 7553, pages 483-488, May 2015.

S. W. Simpson, L. Kleinsasser, J. Quade, N. E. Levin, W. C. McIntosh, N. Dunbar, S. Semaw, and M. J. Rogers. Late Miocene hominin teeth from the Gona Paleoanthropological Research Project area, Afar, Ethiopia. J. Hum. Evol., volume 81, pages 68-82, April 2015.

D. R. Braun, N. E. Levin, D. Stynder, A. I. R. Herries, W. Archer, F. Forrest, D. L. Roberts, L. C. Bishop, T. Matthews, S. B. Lehmann, R. Pickering, and K. E. Fitzsimmons. {Mid-Pleistocene} Hominin occupation at Elandsfontein, Western Cape, South Africa. Quat. Sci. Rev., Elsevier, volume 82, pages 145-166, December 2013.

T. E. Cerling, N. E. Levin, J. Quade, J. G. Wynn, D. L. Fox, J. D. Kingston, R. G. Klein, and F. H. Brown. Comment on the paleoenvironment of Ardipithecus ramidus. Science, volume 328, issue 5982, pages 1105;authorreply1105, May 2010.

N. E. Levin, S. W. Simpson, J. Quade, T. E. Cerling, and S. R. Frost. Herbivore enamel carbon isotopic composition and the environmental context of Ardipithecus at Gona, Ethiopia. The geology of early humans in the Horn of Africa, Geological Society of America Special Paper, volume 446, pages 215-234, 2008.