@article{IM_1996__123_3_144337,
     author = {G\'abor Tardos},
     title = {Towards the {Hanna} {Neumann} conjecture using {Dicks's} method.},
     journal = {Inventiones mathematicae},
     pages = {95--104},
     publisher = {mathdoc},
     volume = {123},
     number = {3},
     year = {1996},
     zbl = {0848.20019},
     url = {http://geodesic.mathdoc.fr/item/IM_1996__123_3_144337/}
}