APA Edition Citation

Radha, S., & Sankhyan, A. S. (2004). Environmental challenges of the 21st century.

Chicago Edition Citation

Radha, S., and Amar Singh Sankhyan. Environmental Challenges of the 21st Century. New Delhi, Deep & Deep Publications, 2004.

MLA Edition Citation

Radha, S., and Amar Singh Sankhyan. Environmental Challenges of the 21st Century. 2004.

Warning: These citations may not always be 100% accurate.