@article{ZR_1998_8_16_a0,
     author = {Bogoljub Stankovi\'c},
     title = {Preface},
     journal = {Zbornik radova},
     pages = {3 },
     publisher = {mathdoc},
     volume = {8},
     number = {16},
     year = {1998},
     url = {http://geodesic.mathdoc.fr/item/ZR_1998_8_16_a0/}
}