Perlman, David. Fossils From Ethiopia May Be Earliest Human Ancestor // National Geographic News, 12 юли 2001. Посетен на July 2009. Another co-author is Tim D. White, a paleoanthropologist at UC-Berkeley who in 1994 discovered a pre-human fossil, named Ardipithecus ramidus, that was then the oldest known, at 4.4 million years.