Cita APA (7th ed.)

Krutch, J. W., & Landacre, P. (2009). The great chain of life (1st University of Iowa Press ed.). University of Iowa Press.

Cita Chicago (17th ed.)

Krutch, Joseph Wood, i Paul Landacre. The Great Chain of Life. 1st University of Iowa Press ed. Iowa City: University of Iowa Press, 2009.

Cita MLA (9th ed.)

Krutch, Joseph Wood, i Paul Landacre. The Great Chain of Life. 1st University of Iowa Press ed. University of Iowa Press, 2009.