Cita APA (7th ed.)

Gopal, B., & Bhardwaj, N. (1979). Elements of ecology. Vikas Publishing House Pvt. Ltd..

Cita Chicago (17th ed.)

Gopal, Brij, i N. Bhardwaj. Elements of Ecology. New Delhi: Vikas Publishing House Pvt. Ltd., 1979.

Cita MLA (9th ed.)

Gopal, Brij, i N. Bhardwaj. Elements of Ecology. Vikas Publishing House Pvt. Ltd., 1979.