Alnomir, Abdo A., Abdo M. Alhadi, Khalid A. Alhakimi, and Ali M. Hadi. “The Effect of Different Levels of Nitrogen Fertilizer on the Growth and Yield of Coffee Trees (Coffea Arabica L.)”. University of Aden Journal of Natural and Applied Sciences 19, no. 1 (April 30, 2015): 129–139. Accessed April 24, 2024. https://uajnas.adenuniv.com/index.php/uajnas/article/view/280.