1. D. H. Krantz, et al, Foundations of Measurement, Academic Press, NYC, NY, 1971. This three volume work is considered to be the "magnum opus" on representational measurement theory by D. J. Hand, Measurement Theory and Practice, Arnold, London England, 2004, page 27.
2. International Vocabulary of Metrology (VIM), third ed., BIPM JCGM 200:2012, http://www.bipm.org/en/publications/guides/vim.html December 2022.
3. L. Euler, Elements of Algebra, Chapter I, Article I, #3. Third edition, Longman, Hurst, Rees, Orme and Co., London England, 1822. Original work published in German in 1765.
4. A. Lyon, Why are Normal Distributions Normal? British Journal of the Philosophy of Science, 65 (2014), 621–649.
5. D. H. Krantz, et al, page 27, 1.5.1 Error of measurement.