Oku, E.; dos Passos, A. M. A. .; Quintino, S. S. .; Odoh, N. C. .; Olowookere, T. B. . Soil Fertility Status of Soils of Sudano-Sahelian and Humid Forest Zones of West Africa and Some Soil Management Strategies for Smallholder Farms. EQA 2021, 46, 25-36.