Radha, S., & Sankhyan, A. S. (2002). Environmental challenges of the 21st century. Deep & Deep.
Chicago Edition CitationRadha, S,Ed, i Amar Singh Sankhyan. Environmental Challenges of the 21st Century. New Delhi: Deep & Deep, 2002.
Cita MLARadha, S,Ed, i Amar Singh Sankhyan. Environmental Challenges of the 21st Century. Deep & Deep, 2002.
Atenció: Aquestes cites poden no estar 100% correctes.