Cita APA (7th ed.)
Darwin, C. R., & Hutchins, R. M. The Origin of Species: By Means of Natural Selection. Encyclopaedia Britannica.
Cita Chicago (17th ed.)
Darwin, Charles R., i Robert Maynard Hutchins. The Origin of Species: By Means of Natural Selection. Chicago, EUA: Encyclopaedia Britannica.
Cita MLA (9th ed.)
Darwin, Charles R., i Robert Maynard Hutchins. The Origin of Species: By Means of Natural Selection. Encyclopaedia Britannica.
Atenció: Aquestes cites poden no estar 100% correctes.