Airy On Tides and Waves, Encycl. Metrop. pp. 364-366.

Outlines of Astronomy, 4th edition, § 538.

Philosophical Magazine, 3rd Series, vol. xxxvii. p. 324.

Letters on the Theory of Probabilities, by Quetelet, translated by O. G. Downes, Notes to Letter XXVI. pp. 286–295.

On the Law of Facility of Errors of Observations, and on the Method of Least Squares, Memoirs of the Royal Astronomical Society, vol. xxxix. p. 75.

Méthode des Moindres Carrés. Mémoires sur la Combinaison des Observations, par Ch. Fr. Gauss. Traduit en Français par J. Bertrand, Paris, 1855, pp. 6, 133, &c.

De Morgan, Penny Cyclopædia, art. Least Squares.

Edinburgh Review, July 1850, vol. xcii. p. 17. Reprinted Essays, p. 399. This method of demonstration is discussed by Boole, Transactions of Royal Society of Edinburgh, vol. xxi. pp. 627–630.

Letters on the Theory of Probabilities, Letter XV. and Appendix, note pp. 256–266.

Encke, On the Method of Least Squares, Taylor’s Scientific Memoirs, vol. ii. pp. 338, 339.

Quetelet, Letters on the Theory of Probabilities, translated by Downes, Letter XIX. p. 88. See also Galton’s Hereditary Genius, p. 379.

System of Logic, bk. iii. chap. 17, § 3. 5th ed. vol. ii. p. 56.

Philosophy of the Inductive Sciences, 2nd ed. vol. ii. pp. 408, 409.

Essay on Probability, Useful Knowledge Society, 1833, p. 41.