@article{IM_1983__71_143005,
     author = {S.M. Gersten},
     title = {Intersections of {Finitely} {Generated} {Subgroups} of {Free} {Groups} and {Resolutions} de {Graphs.}},
     journal = {Inventiones mathematicae},
     pages = {567--592},
     publisher = {mathdoc},
     volume = {71},
     year = {1983},
     zbl = {0521.20014},
     url = {http://geodesic.mathdoc.fr/item/IM_1983__71_143005/}
}