@article{CMH_1980__55_139827,
     author = {Johannes Huebschmann},
     title = {Crossed n-folds extensions of groups and cohomology.},
     journal = {Commentarii mathematici Helvetici},
     pages = {302--313},
     publisher = {mathdoc},
     volume = {55},
     year = {1980},
     zbl = {0443.18019},
     url = {http://geodesic.mathdoc.fr/item/CMH_1980__55_139827/}
}