@article{MABA_1992_6_1_a7,
     author = {D. Cirich and Z. Mijajlovich},
     title = {Class {Spaces}},
     journal = {Mathematica balkanica},
     pages = {91},
     publisher = {mathdoc},
     volume = {6},
     number = {1},
     year = {1992},
     url = {http://geodesic.mathdoc.fr/item/MABA_1992_6_1_a7/}
}