@article{ZR_2000_9_17_a0,
     author = {Bogoljub Stankovi\'c},
     title = {Preface},
     journal = {Zbornik radova},
     pages = {3 },
     publisher = {mathdoc},
     volume = {9},
     number = {17},
     year = {2000},
     url = {http://geodesic.mathdoc.fr/item/ZR_2000_9_17_a0/}
}