@article{JRAM_1982__332_152435,
     author = {D.R. Heath-Brown},
     title = {The least square-free number in an arithmetic progression.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {204--220},
     publisher = {mathdoc},
     volume = {332},
     year = {1982},
     zbl = {0493.10045},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1982__332_152435/}
}