A note on d'Alembert's functional equation
Annales Mathématiques Blaise Pascal, Tome 8 (2001) no. 1, pp. 1-6.
@article{AMBP_2001__8_1_1_0,
     author = {Akkouchi, Mohamed},
     title = {A note on d'Alembert's functional equation},
     journal = {Annales Math\'ematiques Blaise Pascal},
     pages = {1--6},
     publisher = {Laboratoires de Math\'ematiques Pures et Appliqu\'ees de l'Universit\'e Blaise Pascal},
     volume = {8},
     number = {1},
     year = {2001},
     zbl = {0991.39010},
     mrnumber = {1863643},
     language = {en},
     url = {www.numdam.org/item/AMBP_2001__8_1_1_0/}
}
Akkouchi, Mohamed. A note on d'Alembert's functional equation. Annales Mathématiques Blaise Pascal, Tome 8 (2001) no. 1, pp. 1-6. http://www.numdam.org/item/AMBP_2001__8_1_1_0/

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