@article{PIM_1991_N_S_49_63_a23,
     author = {Ljubomir B. \'Ciri\'c},
     title = {On {A} {Common} {Fixed} {Point} {Theorem} {Of} {A} {Gregu\v{s}} {Type}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {174 },
     publisher = {mathdoc},
     volume = {_N_S_49},
     number = {63},
     year = {1991},
     url = {http://geodesic.mathdoc.fr/item/PIM_1991_N_S_49_63_a23/}
}