Amara, D. M. K., P. A. Sawyerr, S. D. Mansaray, and P. J. Kamanda. “Assessment of Soil Productivity Potentials in Hot Semi-Arid Northern Transition Zone of India Using Riquier Index and GIS Techniques”. Asian Journal of Agriculture and Food Sciences, vol. 4, no. 1, Feb. 2016, https://ajouronline.com/index.php/AJAFS/article/view/2921.