1. Comparative studies of trace elements in air particulate in northern Nigeria;Beavington;Science of the Total Environment,1978
2. Global Environment;Berner,1996
3. Brimblecombe, P., 1986. Air Composition and Chemistry. Cambridge University Press, Cambridge, UK.
4. The groundwater hydrology of the Manga Grasslands, northeast Nigeria;Carter;Quarterly Journal of Engineering Geology,1994
5. Environmental Isotopes in Hydrogeology;Clark,1997