APA

Simpson G. G., . (1953). Life of the past: an introduction to paleontology. New Haven: Yale University Press.

Chicago

Simpson George Gaylord, . 1953. Life of the past: an introduction to paleontology. New Haven: Yale University Press.

Harvard

Simpson G. G., . (1953). Life of the past: an introduction to paleontology. New Haven: Yale University Press.

MLA

Simpson George Gaylord, . Life of the past: an introduction to paleontology. New Haven: Yale University Press. 1953.