Ugese, F.D. and Avav, T. (2005) Responses of Mungbean (Vigna radiate) to Phosphorus Application in a Southern Guinea Savanna Location—Nigeria. Journal of Sustainable Tropical Agricultural Research, 13, 77-80.
 Mokwunye, U. and Bationo, A. (2002) Meeting the Phosphorus Needs of the Soil and Crops of West Africa. The Role of Indigenous Phosphate Rocks. In: Integrated Plant Nutrient Management in Sub-Saharan Africa, 352 p.
 Uyovbisere, E.O. and Chude, O.C. (1995) Phosphate Sorption Characteristics of Three Typical Soils from Nigeria as Influenced by Organic Matter and Fe-Oxides. Proceedings of 3rd all African Soil Science Society Conference, 461.
 Nnoke, F.W. (1980) The Use of Phosphorus Sorption Capacity of Soils in Determination of Phosphorus Requirement of Maize in Some Acid Soils of Southern Nigeria. Ph.D. Thesis, University of Nigeria, Nsukka.
 Fox, R.L. and Kamprath, E.J. (1970) Phosphate Sorption Isotherms for Evaluating the Phosphorus Requirement of Soils. Soil Science Society of America Journal, 34, 902-907.
 Murphy, J. and Riley, J.P. (1962) A Modified Single Method for the Determination of Phosphorus in Natural Waters. Analytica Chimica Acta, 27, 31-36.
 Enwezor, W.O., Ohiri, A.C., Opuwaribo, E.E. and Udo, E.J. (1990) Literature Review on Soil Fertility Investigations in Nigeria. Federal Ministry of Agriculture and Natural Resources, Lagos, 460 p.
 Villapando, R.R. and Graetz, D.A. (2001) Phosphorus Sorption and Desorption Properties of the Spodic Horizon from Selected Florida Spodosols. Soil Science Society of America Journal, 65, 331-339.
 Beckwith, R.S. (1965) Sorbed Phosphate at Standard Supernatant Concentration as an Estimate of the Phosphate Needs of Soils. Australian Journal of Experimental Agriculture and Animal Husbandry, 5, 52-58.
 Adeoye, G.O. and Agbola, A.A. (1984) Critical Level for Soil pH, Available P, K, Zn and Mn and Maize Content of P, Cu, and Mn in the Sedimentary Soils of South Western Nigeria. Fertilizer Research, 6, 65-71.
 Aduayi, E.A., Chude, V.O., Adebusuyi, B.A. and Olayiwola, S.O. (2002) Fertilizer Use and Management Practices for Crops in Nigeria. 3rd Edition, Federal Ministry of Agriculture and Rural Development, Abuja, 28-73.
 Breman, H. and Reuler, H.V. (2002) Legumes, When and Where an Option? (No Panacea for Poor Tropical West Africa Soils and Expensive Fertilizers). Integrated Plant Nutrient Management in Sub-Saharan Africa, 352 p.
 Nziguheba, G. (2001) Improving Phosphorus Availability and Maize Production through Organic and Inorganic Amendments in Phosphorus Deficient Soils in Western Kenya. Ph.D. Thesis, Katholicke University of Leuven, Leuven, 118 p.
 Mahmood-ul-Hassan, M., Rashid, A. and Akhtar, M.S. (1993) Phosphorus Requirements of Corn and Sunflower Grown on Calcareous Soils of Pakistan. Communications in Soil Science and Plant Analysis, 24, 1529-1541.
 Bubba, M.O., Arias, C.A. and Brix, H. (2003) Phosphate Adsorption Maximum of Sand Beds as Measured by Langmuir Isotherm Maximum of Sands for Use as Media in Surface Flow Cultivated Reed Beds Measured by Langmuir Isotherm. Water Research, 37, 3390-3400.
 Kuo, S. (1996) Phosphorus. In: Sparks, D.I., Page, A.I., Helmke, P.A., Leoppert, R.H., Soltanpour, P.N., Tabatabbi, M. A., John, C.T. and Summer, M.E., Eds., Chemical Methods of Soil Analysis, Part 3, Soil Science Society of America, American Society of Agronomy, Madison, 869-919.
 Uzoho, B.U. and Oti, N.N. (2005) Estimation of Phosphorus Requirement of Maize (Zea mays) in Selected Soils of South Eastern Nigeria Using P Sorption Isotherm. Nigeria Agricultural Journal, 36, 157-168.
 Siemans, J.H.E., Lang, G.K. and Kaupeenjoham, M. (2004) Adsorption Controls Mobilization of Colloids and Leaching of Dissolved Phosphorus. European Journal of Soil Science, 55, 253-260.