@article{CMH_1980__55_139822,
     author = {Zdzislaw Wojtkowiak},
     title = {Free actions of finite groups on finite {CW} complexes.},
     journal = {Commentarii mathematici Helvetici},
     pages = {225--232},
     publisher = {mathdoc},
     volume = {55},
     year = {1980},
     zbl = {0437.55003},
     url = {http://geodesic.mathdoc.fr/item/CMH_1980__55_139822/}
}