@book{56068,
	author = {Fragoso, M. A. C. and Beusichem, M. L. van and International Colloquium for the Optimization of Plant Nutrition (8 : 1992 : Lisbon, Portugal)},
	title = {Optimization of plant nutrition},
	publisher = {Kluwer,},
	year = {1993},
	series = {Developments in plant and soil sciences v. 53},
	address = {Dordrecht :}
}