1. Abu, B.D. 1987. Living in fear. Newswatch Magazine, Nigeria, Oct. 26, p.32.
2. Akpati, B.N. and Okagbue, C.O. 1988. Ogbajala (Ajala) Hill landslide in Idah Local Government area, Benue State revisited. Report submitted to Natural Hazards Committee, Federal Min. Sci. & Tech. Lagos, Nigeria 8pp.
3. Arnould, M. and Frey, P. 1977. Analyse détaillée des réponses à l’enquête internationale sur les glissements de terrain. Report to Unesco (with Summary in English).
4. Australian Standard 1289. C8.1 – 1980. Methods of testing soils for engineering purposes, Part C—Soil Classification tests.
5. Brabb, E.E. 1989a. Preface. In: Brabb E.E. and Harrod, B.L. (eds). Landslides: extent and economic significance. Balkema Publishers, Rotterdam.