@book{43494,
	author = {Ahmed, Sultana.},
	title = {Availability of zinc and copper in some soils of Bangladesh /},
	publisher = {University of Dhaka ,},
	year = {1989.},
	address = {Dhaka :},
	note = { Thesis (PhD) -- Department. of Soil Science, University of Dhaka, 1989.}
}