Kumra, V. K., Nag, P., & Singh, J. (1997). Geography and environment. Concept Pub.
Citazione stile Chigago Style (17a edizione)Kumra, V. K., Prithvish Nag, e Jagdish Singh. Geography and Environment. New Delhi: Concept Pub, 1997.
Citatione MLA (9a ed.)Kumra, V. K., et al. Geography and Environment. Concept Pub, 1997.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.