@article{MABA_1991_5_2_a2,
     author = {S. M. Mazhar},
     title = {Approximation by {Positive} {Operators} of {Infinite} {Intervals}},
     journal = {Mathematica balkanica},
     pages = {99},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {1991},
     url = {http://geodesic.mathdoc.fr/item/MABA_1991_5_2_a2/}
}