Akinrinde, EA, OA Onanuga, OS Bello, and GO Obigbesan. 2004. “Efficiency of Indigenous Ground Phosphate Rocks, Organic Fertilizer and Their Mixtures for Maize Performance in Two Nigerian Alfisols”. Moor Journal of Agricultural Research 4 (1):1-7. https://doi.org/10.4314/mjar.v4i1.31745.