L. N. Singh, R. K. Singh, A. H. Singh, and Z. Chhangte, “Efficacy of urea in integration with Azolla and vermicompost in rainfed rice (Oryza sativa) production and their residual effect on soil properties*”, Indian J Agri Sci, vol. 75, no. 1, Jan. 2005, Accessed: Oct. 23, 2025. [Online]. Available: https://epubs.icar.org.in/index.php/IJAgS/article/view/9041