Cita APA (7th ed.)

Darwin, C., Barrett, P. H., & Freeman, R. B. (1989). The formation of vegetable mould through the action of worms with observations on their habits. Pickering.

Cita Chicago (17th ed.)

Darwin, Charles, Paul H. Barrett, i R. B. Freeman. The Formation of Vegetable Mould Through the Action of Worms with Observations on Their Habits. London: Pickering, 1989.

Cita MLA (8th ed.)

Darwin, Charles, et al. The Formation of Vegetable Mould Through the Action of Worms with Observations on Their Habits. Pickering, 1989.