@article{PIM_1975_N_S_18_32_a5,
     author = {Ljubomir B. \'Ciri\'c},
     title = {Fixed {And} {Periodic} {Points} {For} {A} {Class} {Of} {Contractive} {Operators}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {57 },
     publisher = {mathdoc},
     volume = {_N_S_18},
     number = {32},
     year = {1975},
     url = {http://geodesic.mathdoc.fr/item/PIM_1975_N_S_18_32_a5/}
}