Kumar, U. (2011). Water, environment and pollution (2.). Agrobios.
Chicago Style aipamenaKumar, U. Water, Environment and Pollution. 2. India: Agrobios, 2011.
MLA aipamenaKumar, U. Water, Environment and Pollution. 2. Agrobios, 2011.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.