@article{MABA_1989_3_3-4_a5,
     author = {O. Trifonov},
     title = {On the {Squarefree} {Problem} {II}},
     journal = {Mathematica balkanica},
     pages = {284},
     publisher = {mathdoc},
     volume = {3},
     number = {3-4},
     year = {1989},
     url = {http://geodesic.mathdoc.fr/item/MABA_1989_3_3-4_a5/}
}