YUSUF, Muhammad Idriss, et al. “Influence of Groundnut Varieties and Bradyrhizobium-Phosphorus Combination on Soil Nitrogen Content in Maiduguri, Nigeria”. Agriculture, Food, and Natural Resources Journal, vol. 5, no. 2, Sept. 2026, pp. 156-63, https://doi.org/10.5281/zenodo.23436052.