1. “Official Methods of Analysis of A.O.A.C.” 14th Ed., Association of Official Analytical Chemists Inc., Virginia, 1984, p. 201.
2. H-O. Beutler, in “Methods of Enzymatic Analysis,” 3rd Ed., Vol. 7, ed. by H. U. Bergmeyer, VCH Verlagsgesellschaft mbH, Weinheim, 1985, pp. 585–591.
3. V. L. Singleton, in “Chemistry of Winemaking,” ed. by A. D. Webb, American Chemical Society, Washington, D.C., 1974, pp. 184 — 211.