“Grain Yield and Yield Components of Single, Double, and Synthetic Maize Lines Grown at Four N Levels in Three Ecological Zones of West Africa. (51)”. Tropical Agriculture 76, no. 1 (January 30, 1999). Accessed December 9, 2024. https://journals.sta.uwi.edu/ojs/index.php/ta/article/view/1488.