References
- Method I: Gray, P. P., and Stone, I. M. Wallerstein Labs. Communs. 5: 5 (1939).
- Method II: De Clerck, J., and Van Cauwenberge, E. H. Wallerstein Labs. Communs. 20: 255 (1957).
- Method III: Owades, J. L., and Zientara, F. Am. Soc. Brewing Chemists, Proc. 1960, p. 68.
- Method IV: Williams, R. S., Murray, D. W., and Quittenton, R. C. Tech. Quart. Master Brewers' Assoc. Am. 4: 1 (1967).
- Color: American Society of Brewing Chemists. Methods of Analysis (6th ed.). The Society: Madison, Wisconsin (1958).