@article{JRAM_1993__437_153506,
     author = {Terry Lawson and Slawomir Kwasik},
     title = {Nonsmoothable {Zp} actions on contractible 4-manifolds.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {29--54},
     publisher = {mathdoc},
     volume = {437},
     year = {1993},
     zbl = {0764.57024},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1993__437_153506/}
}