Ugwuonah, E., and C. Obiora. “Geothermometric and Geobarometric Signatures of Metamorphism in the Precambrian Basement Complex Rocks Around Keffi, North-Central Nigeria”. Ghana Journal of Science, vol. 51, no. 1, May 2015, pp. 73-87, doi:10.4314/gjs.v51i1.