@article{PIM_1975_N_S_19_33_a15,
     author = {Ilija Lazarevi\'c and Alexandru Lupas},
     title = {Approximation {Properties} {Of} {A} {Sequence} {Of} {Linear} {Positive} {Operators}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {89 },
     publisher = {mathdoc},
     volume = {_N_S_19},
     number = {33},
     year = {1975},
     url = {http://geodesic.mathdoc.fr/item/PIM_1975_N_S_19_33_a15/}
}