Cita APA (7th ed.)

Eckholm, E. P. (1978). Disappearing species: The social challenge. Worldwatch Institute.

Cita Chicago (17th ed.)

Eckholm, Erik P. Disappearing Species: The Social Challenge. [Washington]: Worldwatch Institute, 1978.

Cita MLA (8th ed.)

Eckholm, Erik P. Disappearing Species: The Social Challenge. Worldwatch Institute, 1978.