Cita APA (7a ed.)

Gray, J. H. (1970). Biological science: Organisms and population, a laboratory guide. Penguin Books.

Cita Chicago Style (17a ed.)

Gray, John H. Biological Science: Organisms and Population, a Laboratory Guide. Harmondsworth, England, United Kingdom: Penguin Books, 1970.

Cita MLA (9a ed.)

Gray, John H. Biological Science: Organisms and Population, a Laboratory Guide. Penguin Books, 1970.