@article{10_1090_S0894_0347_1990_1044058_X,
     author = {Wahl, Jonathan},
     title = {A characteristic number for links of surface singularities},
     journal = {Journal of the American Mathematical Society},
     pages = {625--637},
     publisher = {mathdoc},
     volume = {03},
     number = {3},
     year = {1990},
     doi = {10.1090/S0894-0347-1990-1044058-X},
     url = {http://geodesic.mathdoc.fr/articles/10.1090/S0894-0347-1990-1044058-X/}
}