[[1] ACZÉL, J.—DHOMBRES, J.: Functional Equations in Several Variables. Cambridge University Press, Cambridge, 1989.10.1017/CBO9781139086578]Search in Google Scholar
[[2] DHOMBRES, J.: Relations de dépendance entreéquations fonctionnelles de Cauchy, Aequationes Math. 35 (1988), 186–212.10.1007/BF01830943]Search in Google Scholar
[[3] GER, R.: On an equation of ring homomorphisms, Publ. Math. Debrecen 52 (1998), 397–417.10.5486/PMD.1998.2046]Search in Google Scholar
[[4] _______ Ring homomorphisms equation revisited, Rocznik Nauk.-Dydakt. Prace Mat 17 (2000), 101–115.]Search in Google Scholar
[[5] GER, R.—REICH, L.: A generalized ring homomorphisms equation, Monatsh. Math. 159 (2010), no. 3, 225–233.10.1007/s00605-009-0173-4]Search in Google Scholar
[[6] GER, R.—SABLIK, M.: Alien functional equations: a selective survey of results. In: Developments in Functional Equations and Related Topics (J. Brzdęk, et al. eds.), thevolumededicated to thememoryofStanisław Marcin Ulam, Springer Optim. Appl. Vol. 124, Springer International Publishing AG 2017, pp. 107–147.10.1007/978-3-319-61732-9_6]Search in Google Scholar
[[7] KUCZMA, M.: Functional Equations in a Single Variable. Monografie Mat. Vol. 46. Polish Scientific Publishers, Warsaw, 1968.]Search in Google Scholar
[[8] KUCZMA, M.—CHOCZEWSKI, B.—GER, R.: Iterative Functional Equations. Cambridge University Press, Cambridge, 1990.10.1017/CBO9781139086639]Search in Google Scholar
[[9] LISAK, A.—SABLIK, M.: Trapezoidal rule revisited, Bull. Inst.Math. Acad.Sin.(N.S.) 6 (2011), 347–360.]Search in Google Scholar
[[10] SABLIK, M.: A remark on a mean value property, C. R. Math. Rep. Acad. Sci. Canada 14 (1992), 207–212.]Search in Google Scholar
[[11] _______ Taylor’s theorem and functional equations, Aequationes Math. 60 (2000), 258–267.10.1007/s000100050152]Search in Google Scholar
[[12] SZÉKELYHIDI, L.: Convolution Type Functional Equations on Topological Commutative Groups. World Scientific Publishing Co., Inc., Teaneck, NJ, 1991.10.1142/1406]Search in Google Scholar
