@article{10_4153_CMB_1982_039_1,
     author = {Hardy, G. E. and Subbarao, M. V.},
     title = {Semi {r-Free} and {r-Free} {Integers{\textemdash}A} {Unified} {Approach}},
     journal = {Canadian mathematical bulletin},
     pages = {273--290},
     year = {1982},
     volume = {25},
     number = {3},
     doi = {10.4153/CMB-1982-039-1},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1982-039-1/}
}