@article{MAN_1977__225_162935,
     author = {Martin Scharlemann},
     title = {The {Fundamental} {Group} of {Fibered} {Knot} {Cobordisms.}},
     journal = {Mathematische Annalen},
     pages = {243--252},
     publisher = {mathdoc},
     volume = {225},
     year = {1977},
     zbl = {0325.55001},
     url = {http://geodesic.mathdoc.fr/item/MAN_1977__225_162935/}
}