Ahmad, M., Khan, I., Muhammad, D., Mussarat, M., & Shafi, M. I. (2019). Effect of Phosphorus Sources and their Levels on Spring Maize: Effect of Phosphorus on Spring Maize. Biological Sciences - PJSIR, 62(1), 8–14. https://doi.org/10.52763/PJSIR.BIOL.SCI.62.1.2019.8.14