@book{30485,
	author = {Symposium on Research into Agro-technical Methods Aiming at Increasing the Productivity of Crops--Co-efficients for the Most Efficient Use of Fertilizer Nutrients and Means for Reducing the Losses of Nutrients to the Environment under the Conditions of Intensive Agriculture and United Nations.},
	title = {Efficient use of fertilizers in agriculture /},
	publisher = {Martinus Nijhoff/Dr. W. Junk for the United Nations},
	year = {c1983.},
	series = {Developments in plant and soil sciences ;},
	address = {Boston :},
	note = {English and French.}
}