Udo, Reuben K.. "14 The Benue Valley". Geographical Regions of Nigeria, Berkeley: University of California Press, 1970, pp. 138-148. https://doi.org/10.1525/9780520327108-019
Udo, R. (1970). 14 The Benue Valley. In Geographical Regions of Nigeria (pp. 138-148). Berkeley: University of California Press. https://doi.org/10.1525/9780520327108-019
Udo, R. 1970. 14 The Benue Valley. Geographical Regions of Nigeria. Berkeley: University of California Press, pp. 138-148. https://doi.org/10.1525/9780520327108-019
Udo, Reuben K.. "14 The Benue Valley" In Geographical Regions of Nigeria, 138-148. Berkeley: University of California Press, 1970. https://doi.org/10.1525/9780520327108-019
Udo R. 14 The Benue Valley. In: Geographical Regions of Nigeria. Berkeley: University of California Press; 1970. p.138-148. https://doi.org/10.1525/9780520327108-019