@article{CMH_1980__55_139828,
     author = {Johannes Huebschmann},
     title = {The first k-invariant, {Quillen's} space {BG+} and the construction of {Kann} and {Thurston.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {314--318},
     publisher = {mathdoc},
     volume = {55},
     year = {1980},
     zbl = {0443.18017},
     url = {http://geodesic.mathdoc.fr/item/CMH_1980__55_139828/}
}