Sinha, Parmeshwar, and Kali Pada Das Gupta. “Crop Responses to Added Fertilizers inCultivators’ Fields-A Technique for Finding Out Manurial Requirements of Bihar Soils”. Journal of Soil and Water Conservation, vol. 4, no. 3, July 2022, https://epubs.icar.org.in/index.php/JSWC/article/view/125945.