@article{AM2_1986__30_137112,
     author = {Pavel Kostyrko},
     title = {On a local form of {Jensen's} functional equation.},
     journal = {Aequationes mathematicae},
     pages = {65--69},
     publisher = {mathdoc},
     volume = {30},
     year = {1986},
     zbl = {0594.39006},
     url = {http://geodesic.mathdoc.fr/item/AM2_1986__30_137112/}
}