@article{GDZPPN00203526X, title = {A vector functional equation and linear differential equations.}, journal = {Aequationes mathematicae}, volume = {28}, year = {1985}, pages = {19-23}, zbl = {0593.39006}, url = {http://dml.mathdoc.fr/item/GDZPPN00203526X} }
Neumann, Frantisek. A vector functional equation and linear differential equations.. Aequationes mathematicae, Tome 28 (1985) pp. 19-23. http://gdmltest.u-ga.fr/item/GDZPPN00203526X/