Cita APA

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

Citación estilo Chicago

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

Cita MLA

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