@article{PIM_1978_N_S_23_37_a11,
     author = {Aleksandar Ivi\'c},
     title = {On {The} {Asymptotic} {Formulas} {For} {Powerful} {Numbers}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {85 },
     publisher = {mathdoc},
     volume = {_N_S_23},
     number = {37},
     year = {1978},
     url = {http://geodesic.mathdoc.fr/item/PIM_1978_N_S_23_37_a11/}
}