@book{640,
	author = {Tolba, Mostafa K.},
	title = {The earth summit and Africa's development /},
	publisher = {International Institute of Tropical Agriculture,},
	year = {1993},
	address = {Ibadan, Nigeria :},
	note = {"Delivered at the International Institute of Tropical Agriculture, Ibadan, on 28 April 1993."}
}