@article{IM_1983__73_143042,
     author = {Y.-N. Gau and J. Lipman},
     title = {Differential {Invariance} of {Multiplicity} of {Analytic} {Varieties.}},
     journal = {Inventiones mathematicae},
     pages = {165--188},
     publisher = {mathdoc},
     volume = {73},
     year = {1983},
     zbl = {0498.32003},
     url = {http://geodesic.mathdoc.fr/item/IM_1983__73_143042/}
}