Reddy, R. Uma, and M. Suryanarayan Reddy. “Availability of Major Nutrients in Soil As Influenced by Integrated Nutrient Management in Tomato-Onion Cropping System”. Indian Journal of Horticulture, vol. 68, no. 02, June 2011, pp. 224-8, https://journal.iahs.org.in/index.php/ijh/article/view/1888.