A generalization of d'Alembert's functional equation

MR1065469 Gajda, Zbigniew Zbigniew GAJDA A generalization of d'Alembert's functional equation Funkcialaj Ekvacioj. Serio Internacia 33 1990 69--77 http://fe.math.kobe-u.ac.jp/FE/Free/vol33/fe33-1-5.pdf http://fe.math.kobe-u.ac.jp/FE/FE_pdf_with_bookmark/FE31-34-en_KML/fe33-069-077/fe33-069-077.pdf http://www.ams.org/mathscinet-getitem?mr=MR1065469 fe33-069-077 1990 A Generalization of D'Alembert's Functional Equation GAJDA, Zbigniew GAJDA, Zbigniew 1 Aczél, J. Lectures on functional equations and their applications Academic Press, New York-San Francisco-London 1966 MR0208210 100 Cache/Ac/Aczél,applications,*,1966,1967 xx+510

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