M. Prabhavathi, et al. “Identification of Soil Fertility Constraints Using GIS for Sustainable Crop Production in the Watershed of Semi-Arid Tropics”. Journal of the Indian Society of Soil Science, vol. 71, no. 2, Aug. 2023, pp. 159-71, https://epubs.icar.org.in/index.php/JISSS/article/view/140789.