Cita APA (7th ed.)

Kumra, V. K., Nag, P., & Singh, J. (1997). Geography and environment. Concept Pub.

Cita Chicago (17th ed.)

Kumra, V. K., Prithvish Nag, i Jagdish Singh. Geography and Environment. New Delhi: Concept Pub, 1997.

Cita MLA (9th ed.)

Kumra, V. K., et al. Geography and Environment. Concept Pub, 1997.