@article{PIM_1963_N_S_03_17_a7,
     author = {M. Hossz\'u},
     title = {On {A} {Class} {Of} {Functional} {Equations}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {53 },
     year = {1963},
     volume = {_N_S_03},
     number = {17},
     url = {http://geodesic.mathdoc.fr/item/PIM_1963_N_S_03_17_a7/}
}