@article{PIM_1988_N_S_43_57_a10,
     author = {Jovan D. Ke\v{c}ki\'c},
     title = {On a {System} of {Functional} {Equations}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {85 - 91},
     publisher = {mathdoc},
     volume = {(N.S.) 43},
     number = {57},
     year = {1988},
     url = {https://geodesic-test.mathdoc.fr/item/PIM_1988_N_S_43_57_a10/}
}