@article{MABA_2005_19_1-2_a11,
     author = {Ljubisa D.R. Kocinac},
     title = {?-Sets, {Yk-Sets} and {Hyperspaces}},
     journal = {Mathematica balkanica},
     pages = {109},
     publisher = {mathdoc},
     volume = {19},
     number = {1-2},
     year = {2005},
     url = {http://geodesic.mathdoc.fr/item/MABA_2005_19_1-2_a11/}
}