APA (7th ed.) Citation

Darwin, C. (1966). On the origin of species (A facs. of the 1. ed., 2. print.). Harvard Univ. Press.

Chicago Style (17th ed.) Citation

Darwin, Charles. On the Origin of Species. A facs. of the 1. ed., 2. print. Cambridge, Mass: Harvard Univ. Press, 1966.

MLA (9th ed.) Citation

Darwin, Charles. On the Origin of Species. A facs. of the 1. ed., 2. print. Harvard Univ. Press, 1966.