@book{25393,
	author = {Rajan, S.V. Govinda   and Rao, H.G. Gopala },
	title = { Soil and crop productivity a handbook for the use of workers in agricultural extension, vocational agriculture and farmers in India/by S.V. Govind Rajan and H.G. Gopala Rao},
	publisher = {Asia Publishing House, },
	year = {1971.},
	address = {Bombay: }
}