@article{MZ_1994__217_1_174694,
     author = {Dariusz, M. Wilczynski},
     title = {On the topological classification of pseudofree group actions on 4-manifolds. {I.}},
     journal = {Mathematische Zeitschrift},
     pages = {335--366},
     publisher = {mathdoc},
     volume = {217},
     number = {1},
     year = {1994},
     zbl = {0813.57030},
     url = {http://geodesic.mathdoc.fr/item/MZ_1994__217_1_174694/}
}