@article{GDZPPN00203431X, title = {On systems of linear functional equations.}, journal = {Aequationes mathematicae}, volume = {26}, year = {1983}, pages = {64-73}, zbl = {0533.39005}, url = {http://dml.mathdoc.fr/item/GDZPPN00203431X} }
Laird, P.G.; Mills, J. On systems of linear functional equations.. Aequationes mathematicae, Tome 26 (1983) pp. 64-73. http://gdmltest.u-ga.fr/item/GDZPPN00203431X/