Chitkara, M. (1997). Encyclopaedia of ecology, environment and pollution: Vol-xii the environment (protection) act, 1986; the environment (protection) rules, 1986 and notifications. APH Publishing.

Chitkara, M.G. Encyclopaedia of Ecology, Environment and Pollution: Vol-xii the Environment (protection) Act, 1986; the Environment (protection) Rules, 1986 and Notifications. New Delhi: APH Publishing, 1997.

Chitkara, M.G. Encyclopaedia of Ecology, Environment and Pollution: Vol-xii the Environment (protection) Act, 1986; the Environment (protection) Rules, 1986 and Notifications. APH Publishing, 1997.