Cita APA (7th ed.)

Usher, M. B., & Williamson, M. H. (1974). Ecological stability. Chapman.

Cita Chicago (17th ed.)

Usher, M. B., i M. H. Williamson. Ecological Stability. London, United Kingdom: Chapman, 1974.

Cita MLA (9th ed.)

Usher, M. B., i M. H. Williamson. Ecological Stability. Chapman, 1974.