Literature Cited

Alvarez, L. W., W. Alvarezy, F. Asaro, and H. V. Michel. 1980. "Extraterrestrial cause for the Cretaceous-Tertiary extinction." Science 208:1095-1108.

Archibald, J. D., and W. A. Clemens. 1982. "Late Cretaceous extinctions." American Scientist 70:377-385.