1. Abrol, D.P., & Shankar, D.A.U. (2015). Role of pollination in pulses. Advanced in pollen spore research Vol. XXXIII:101-103. Today & Tommorow’s Printers and punlishers, New Delhi- 110 002
2. Admassu, A., & Nuru, A. (2000). The effect honeybee pollination on seed and oil content of Guizotia abyssinica L, In First National Conference of Ethiopian Beekeepers Association, Addis Ababa Ethiopia.
3. Bauer, D.M., & Wing, I.S. (2010). Economic consequences of pollinator declines: a synthesis. Agricultural and Resource Economics Review, 39(3), 368-383.10.1017/S1068280500007371
4. Council, N.R. (2007). Status of pollinators in North America.
5. Central Statistical Agency Agricultural Sample Survey 2015/16. (2016) Volume I Report on Livestock and Livestock Characteristics