Hazewinkel, Gubareni & Kirichenko 2004, p. 2 Hazewinkel, Michiel; Gubareni, Nadiya; Kirichenko, V. V. (2004), Algebras, rings and modules. Vol. 1, Mathematics and its Applications, vol. 575, Dordrecht: Kluwer Academic Publishers, pp. xii+380, ISBN1-4020-2690-0, MR2106764