S.S. Singh Principles and Practices of Agronomy - Ludhiyana Kalyani Publishers 1988 - 409p S.S. Singh: Principles and Practices of Agronomy. Ludhiyana. Kalyani Publishers, 1988. 81-7663-858-7--(630SIN) ENGLISH ISBN: 81-7663-858-7 Dewey Class. No.: 630 / SIN