@article{MAN_1993__296_4_165102,
     author = {Daniel S. Silver},
     title = {Augmented group systems and n-knots.},
     journal = {Mathematische Annalen},
     pages = {585--594},
     publisher = {mathdoc},
     volume = {296},
     number = {4},
     year = {1993},
     zbl = {0793.57012},
     url = {http://geodesic.mathdoc.fr/item/MAN_1993__296_4_165102/}
}