Ancient and medieval history of Indian agriculture and its relevance to sustainable agriculture in the 21st century proceeding of t he sumer school held from 28 May to 17 June 1999, Rajasthan collage of Agriculture, Udaypur - Choudhary, S.L., ed.; Nene, Y.L., ed.; Sharma, G.S., ed. (Rajasthan College of Agriculture Udaipur, 2000)