1. Bares, R. H. & Wali, M. K. 1979. Chemical relations and litter production of Picea mariana and Larix laricina stands on an alkaline peatland in northern Minnesota. Vegetatio 40: 79?94.
2. Braun-Blanquet, J. 1932. Plant sociology (Transl. G. D. Fuller & H. S. Conard). McGraw-Hill Book Co., N.Y. 439 p.
3. Res. Br., Can. Dept. Agr. Publ.;CSSC (Canadian Soil Survey Committee),1978
4. Dahl, E. 1956. Rondane: Mountain vegetation in south Norway and its relation to the environment. Norsk. Vidensk. Akad., Oslo, Matem.-natur. Skrift. 1956(3): 1?374.
5. FAO-UNESCO. 1974. Soil map of the world. Vol. I, Legend. UNESCO, Paris. 59 p.