1. Adeleye DR (1973) Origin of ironstones: an example from the Middle Niger Valley Nigeria. J Sedimentol Petrol 43:709–727
2. Ajaegwu NE, Odoh BI, Akpunonu EO, Obiadi II, Anakwuba EK (2012) Late Miocene to early Pliocene Palynostratigraphy and Palaeoenvironments of ANE-1 Well, Eastern Niger Delta Nigeria. J Mining Geol 48(1):31–43
3. Bawden MG (1972) Geomorphology. The land resources of the North East Nigeria Vol 1–5. In: Tuley P (eds) Land resources division Tolworth tower surbiton Surrey, England
4. Bennett JG, Hutcheon AA, Kerr WB, Mansfield JE, Rackham LJ (1977) Environmental aspects of the Kaduna plains, land forms and soils, land resources report 19, Land Resources Division, Surrey, UK, 1977
5. Buchanan KM (1955) Land and people in Nigeria. Lincoln Ltd United Kingdom