@misc{RCM_2010_44_1_a4,
     title = {An {Alternative} {Proof} of {Hill's} {Criterion} of {Freeness} for {Abelian} {Groups}},
     journal = {Revista colombiana de matematicas},
     pages = {59--64},
     publisher = {mathdoc},
     volume = {44},
     number = {1},
     year = {2010},
     url = {http://geodesic.mathdoc.fr/item/RCM_2010_44_1_a4/}
}