P R Sivaraman , C Kamalakannan. “Smart Irrigation System With GSM Module Using DC-DC Converter With Regenerative Snubber”. International Journal of Emerging Trends in Science and Technology, Vol. 4, no. 09, Sept. 2017, pp. 5874-8, http://igmpublication.org/ijetst.in/index.php/ijetst/article/view/1360.