@article{CMH_1976__51_139667,
     author = {Sylvain E. Cappell and Julius L. Shaneson},
     title = {Fundamental {Groups,} ...-groups and {Codimension} two {Submanifolds}},
     journal = {Commentarii mathematici Helvetici},
     pages = {437--446},
     publisher = {mathdoc},
     volume = {51},
     year = {1976},
     zbl = {0362.57002},
     url = {http://geodesic.mathdoc.fr/item/CMH_1976__51_139667/}
}