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2. H. Fraenkel-Conrat, J. I. Harris and A. L. Levy, “Methods of Biochemical Analysis,” Vol. 2, ed. D. Glick, Interscience Publishers Inc., New York, 1955, p. 359.
3. T. Kaneko, Abstracts of Papers, p. 19, The 4th Meeting of the Symposium on Taste and Smell, Kumamoto, Japan, November 3, 1970.