@article{IM_1971__14_142112,
     author = {R. Lashof and J.L. Shaneson},
     title = {Smoothing {4-Manifolds.}},
     journal = {Inventiones mathematicae},
     pages = {197--210},
     publisher = {mathdoc},
     volume = {14},
     year = {1971},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM_1971__14_142112/}
}