Houston, W.R. 1961. Some interrelations of sagebrush, soils and grazing 

 intensities in the Northern Great Plains. Ecology 42:31-38. 



, and R. R. Woodward. 1966. Effects of stocking rates on range 



vegetation and beef cattle production in the Northern Great Plains. 

 U.S. Department of Agriculture Technical Bulletin 1357. 58 pp. 



Hull, d. 1974. Philosophy of biological science. Prentice-Hall. 

 Englewood Cliffs, N.J. 148 pp. 



Jaccard, P. 1928. Die statistisch-floristische methode als grundlage der 

 planzensoziologie, hi^. Abderhalden, Handbi bid. Arbeitsmeth. 11:165-202. 



Jameson, D. and D. Huss. 1959. The effect of clipping leaves and stems on 

 number of tillers, herbage weights, not weights, and food reserves of 

 little bluestem. Journal of Range Management. 12:122-126. 



Kelly, J., Van Dyne, G. , and W. Harris, 1974. Comparison of three methods 



of assessing grassland productivity and biomass dynamics. American Midland 

 Naturalist. 92:357-369. 



Kucera, C. 1973. The challenge of ecology. C.V. Mosby Co. St. Louis. 226 pp. 



Kuchler, A. W. 1964. Potential natural vegetation of the conterminous United 

 States. American Geographic Society Special Publication No. 36. 116 pp. 

 and map. 



, 1969. Natural and Cultural Vegetation. The Professional Geographer 



2TT6):383-385. 



Lambert, J.M. and M.B. Dale, 1964. The use of statistics in phytosociology. 

 Advancements in Ecology. Vol 11:55-99. 



Lommasson, T. 1947. The influence of rainfall on the prosperity of eastern 

 Montana 1878-1946. Developments in Range Management. U.S. Department of 

 Agriculture, Forest Service Region One. 



Mcintosh, R.P. 1967. The continuum concept of vegetation. Botanical Review. 

 33:130-187. 



McMillan, C. 1959. The role of ecotypic variations in the distribution of 

 the central grasslands of North America. Ecological Monographs. 

 29(4):285-308. 



, 1969. Ecotypes and ecosystem function. Bio Science. 9(2) :131-134. 



Mitchell, J. and R. Pfadt. 1974. A role of grasshoppers in a shortgrass 

 prairie ecosystem. Environmental Entomology. 3(2):358-360. 



Morris, M.S. 1945. (Revised 1976) Ecological basis for the classification 

 of Montana grasslands. Proceedings of the Montana Academy of Sciences. 

 5:41-44. 



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