@article{MABA_2014_28_1-2_a3,
     author = {Vesko Valov},
     title = {Averaging operators and set-valued maps},
     journal = {Mathematica balkanica},
     pages = {57},
     publisher = {mathdoc},
     volume = {28},
     number = {1-2},
     year = {2014},
     url = {http://geodesic.mathdoc.fr/item/MABA_2014_28_1-2_a3/}
}