Mallikarjun B Halli.,1, Anil Kumar V, Basavaraju UK, Yadhunandan TN, Rajesh J. “Real Time Monitering of Soil Nutrients ”. International Journal of Advanced Science and Technology, Vol. 29, no. 10s, June 2020, pp. 4059-63, http://sersc.org/journals/index.php/IJAST/article/view/21072.