The term center or centre is used in various contexts in abstract algebra to denote the set of all those elements that commute with all other elements.
^Kilp, Mati; Knauer, Ulrich; Mikhalev, Aleksandr V. (2000). Monoids, Acts and Categories. De Gruyter Expositions in Mathematics. Vol. 29. Walter de Gruyter. p. 25. ISBN 978-3-11-015248-7.
^Ljapin, E. S. (1968). Semigroups. Translations of Mathematical Monographs. Vol. 3. Translated by A. A. Brown; J. M. Danskin; D. Foley; S. H. Gould; E. Hewitt; S. A. Walker; J. A. Zilber. Providence, Rhode Island: American Mathematical Soc. p. 96. ISBN 978-0-8218-8641-0.
^Durbin, John R. (1993). Modern Algebra: An Introduction (3rd ed.). John Wiley and Sons. p. 118. ISBN 0-471-51001-7. The center of a ring R is defined to be {c ∈ R: cr = rc for every r ∈ R}., Exercise 22.22