@article{MM2_1992__74_2_155693,
     author = {B. Heinrich Matzat},
     title = {Zopfgruppen und {Einbettungsprobleme.}},
     journal = {Manuscripta mathematica},
     pages = {217--228},
     year = {1992},
     volume = {74},
     number = {2},
     url = {http://geodesic.mathdoc.fr/item/MM2_1992__74_2_155693/}
}