Effa, Emmanuel B., et al. “Spatial Dimensions and Poultry Manure Rate Effects on Sweet Corn (Zea Mays L. Saccharata Sturt.) Varieties in Calabar”. Journal Of Agriculture, Forestry & Environment , vol. 5, no. 1, Mar. 2025, pp. 48-57, https://jafe.net.ng/index.php/home/article/view/52.