@article{10_4064_cm_82_1_117_123,
     author = {Zolt\'an Dar\'oczy and Gyula Maksa},
     title = {On a problem of {Matkowski}},
     journal = {Colloquium Mathematicum},
     pages = {117--123},
     publisher = {mathdoc},
     volume = {82},
     number = {1},
     year = {1999},
     doi = {10.4064/cm-82-1-117-123},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-82-1-117-123/}
}