@article{IM_1971__13_142101,
     author = {W. Jaco},
     title = {Finitely {Presented} {Subgroups} of {Three-Manifold} {Groups.}},
     journal = {Inventiones mathematicae},
     pages = {335--346},
     publisher = {mathdoc},
     volume = {13},
     year = {1971},
     zbl = {0232.57003},
     url = {http://geodesic.mathdoc.fr/item/IM_1971__13_142101/}
}