Kumra, V. K., Nag, P., & Singh, J. (1997). Geography and environment. Concept Pub.
Cita Chicago Style (17a ed.)Kumra, V. K., Prithvish Nag, y Jagdish Singh. Geography and Environment. New Delhi: Concept Pub, 1997.
Cita MLA (9a ed.)Kumra, V. K., et al. Geography and Environment. Concept Pub, 1997.
Precaución: Estas citas no son 100% exactas.