Gaya APA

Raup, D, M., M., I, S, S. (NULL). Principles of paleontology . San: San Francisco: W.H. Freeman and Co.; 1971.

Gaya MLA

Raup, David, M.., M., I., Stanley,, Steven. "Principles of paleontology". San: San Francisco: W.H. Freeman and Co.; 1971, NULL. Text.