1. Arnott, H.J., Pautard, F.G.E.: Calcification in plants. In: Biological calcification (H. Schraer, ed.), p. 375?446. New York: Appleton-Century-Crofts 1970
2. Barrow, G.M.: Physical chemistry, 3rd ed. New York: McGraw-Hill 1973
3. Bliss, L.C.: Caloric and lipid content in alpine tundra plants. Ecology43, 753?754 (1962)
4. Couch, J.F.: The toxic constituent of greasewood (Sarcobatus vermiculatus). Amer. J. Pharm.94, 631?641 (1922)
5. Darling, M.S.: Structure and productivity of a pinyon-juniper woodland in northern Arizona. Ph.D. thesis, Duke University, Durham, N.C. (1966)