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Pearson , E. S. 88London: British Standards Institution. Ash content data
2. British Standard 5703: Part 2. 1980. Guide to Data Analysis and Quality Control Using Cusum Techniques: decision rules and statistical tests for cusum charts and tabulations, 18–19. London: British Standards Institute. evaluation of blender
3. Hald , A. 1952. Statistical Theory with Engineering Applications, 357–360. New York: John Wiley.
4. Tabulation of the Probabilities for the Ratio of the Mean Square Successive Difference to the Variance