交換法則
↑ Lumpkin 1997, p. 11.
↑ Robins & Shute 1987, p. ?.
↑ O'Conner and Robertson, Real Numbers
↑ Cabillón & Miller, Commutative and Distributive.
↑ O'Conner & Robertson, Servois.
↑ Commutative - PlanetMath.(英語)
↑ Weisstein, Eric W. "Commutative". mathworld.wolfram.com (英語).
↑ Gallian 2006, p. 34.
↑ Gallian 2006, p. 236.
↑ Gallian 2006, p. 250.
↑ Axler 1997, p. 2.
↑ Gallian 2006, pp. 26, 34, 87.