Singh, S.S. Principles and practices of agronomy / S.S. Singhand Rajesh Singh. - Ludhiana : Kalyani, 1988. - xii, 409 pages. : illustrations ; 19 cm. Includes indexes and bibliography. ISBN: 9789327256376 : $ 40.00 Subjects--Topical Terms: Field crops.Agronomy.Agriculture.