Voir la notice de l'article provenant de la source Hellenic Digital Mathematics Library
@article{EUG_1991__28_a3, author = {Pavlos Sinopoulos}, title = {A {New} {Generalization} of {Sine} and cosine functional equations}, journal = {E\ensuremath{\upsilon}\ensuremath{\kappa}\ensuremath{\lambda}\ensuremath{\varepsilon}\ensuremath{\acute\iota}\ensuremath{\delta}\ensuremath{\eta}\ensuremath{\varsigma} \ensuremath{\Gamma} }, pages = {43-49}, publisher = {mathdoc}, volume = {28}, year = {1991}, language = {gr}, url = {http://geodesic.mathdoc.fr/item/EUG_1991__28_a3/} }
Pavlos Sinopoulos. A New Generalization of Sine and cosine functional equations. Ευκλείδης Γ , Tome 28 (1991), p. 43-49. http://geodesic.mathdoc.fr/item/EUG_1991__28_a3/