@article{IM_1982__69_142955,
     author = {H. M\"uller and B. Eckman},
     title = {Plane {Motion} {Groups} and {Virtual} {Poincar\'e} {Duality} of {Dimension} {Two.}},
     journal = {Inventiones mathematicae},
     pages = {293--310},
     publisher = {mathdoc},
     volume = {69},
     year = {1982},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM_1982__69_142955/}
}