@book{412569,
	author = {Zafar, A. R.},
	title = {Biological indicators and indices of environmental pollution: proceedings of the workshop held at Osmania University, Hyderabad, India during 21-23 September, 1981 under a who grant},
	publisher = {Central Board for the prevention and control of water pollution},
	year = {1982},
	address = {New Delhi}
}