@article{MZ_1984__187_173495,
     author = {D.R. Heath-Brown},
     title = {Diphantine {Approximation} with {Square-free} {Numbers.}},
     journal = {Mathematische Zeitschrift},
     pages = {335--344},
     publisher = {mathdoc},
     volume = {187},
     year = {1984},
     zbl = {0539.10026},
     url = {http://geodesic.mathdoc.fr/item/MZ_1984__187_173495/}
}