8Gross, B. D. , Holechek, J. L. , Hallford, D. , & Pieper, R. D. (1983). Effectiveness of antelope pass structures in restriction of livestock [J]. Journal of Range Management,36( 1 ) :22 -24.
9Wilson, R. T. (1980). Livestock production in central Mali: Structure of the herds and flocks and some related demographic parameters [ R]. Report : ILCA Mall Progranmw Document.