@article{10_4153_CMB_1991_022_3,
     author = {W\"urfel, Tilmann},
     title = {Dimension-Preserving {Extensions} of {Pro-p-Groups}},
     journal = {Canadian mathematical bulletin},
     pages = {136--140},
     year = {1991},
     volume = {34},
     number = {1},
     doi = {10.4153/CMB-1991-022-3},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1991-022-3/}
}