@article{10_4064_fm_44_3_303_308,
     author = {Stanis{\l}aw Balcerzyk and Jan Mycielski},
     title = {On the existence of free subgroups in topological groups},
     journal = {Fundamenta Mathematicae},
     pages = {303--308},
     publisher = {mathdoc},
     volume = {44},
     number = {3},
     year = {1957},
     doi = {10.4064/fm-44-3-303-308},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-44-3-303-308/}
}