1. Processing Data for Outliers
2. Dixon, W. J., and Massey, F. J., Jr. Introduction to Statistical Analysis, p. 470. McGraw-Hill: New York, 1969.
3. European Brewery Convention. Analytica-EBC (3rd ed.). Method 7.11, p. E73. Schweizer Brauerei-Rundschau: Zurich, Switzerland, 1975.