Gurjar, D S, and B R Yadav. “Seasonal Variation in PH, Salinity, Nitrate, Fluoride and Heavy Metals in Irrigated Soils of South-West Region of Delhi, India”. Journal of the Indian Society of Soil Science, vol. 61, no. 1, July 2013, https://epubs.icar.org.in/index.php/JISSS/article/view/31751.