APA

Keeton W. T., Gould J. L. & Grant Gould C. (1993). Biological science. New York, USA: W. W. Norton and Company.

Chicago

Keeton William T, Gould James L and Grant Gould Carol. 1993. Biological science. New York, USA: W. W. Norton and Company.

Harvard

Keeton W. T., Gould J. L. and Grant Gould C. (1993). Biological science. New York, USA: W. W. Norton and Company.

MLA

Keeton William T, Gould James L and Grant Gould Carol. Biological science. New York, USA: W. W. Norton and Company. 1993.