Key points are not available for this paper at this time.
Robert E. Williams, B. W. Allred, Reginald M. Denio, Harold A. Paulsen, Jr., Conservation, Development, and Use of the World's Rangelands, Journal of Range Management, Vol. 21, No. 6 (Nov., 1968), pp. 355-360
Williams et al. (Fri,) studied this question.