@article{MM2_1989__63_3_155374,
     author = {Mario Salvetti},
     title = {On the number of non-equivalent differentiable structures on {4-Manifolds.}},
     journal = {Manuscripta mathematica},
     pages = {157--172},
     publisher = {mathdoc},
     volume = {63},
     number = {3},
     year = {1989},
     zbl = {0682.14026},
     url = {http://geodesic.mathdoc.fr/item/MM2_1989__63_3_155374/}
}