@article{10_1090_S0894_0347_99_00294_5,
     author = {Spivakovsky, Mark},
     title = {A new proof of {D.} {Popescu\^a€™s} theorem on smoothing of ring homomorphisms},
     journal = {Journal of the American Mathematical Society},
     pages = {381--444},
     publisher = {mathdoc},
     volume = {12},
     number = {2},
     year = {1999},
     doi = {10.1090/S0894-0347-99-00294-5},
     url = {http://geodesic.mathdoc.fr/articles/10.1090/S0894-0347-99-00294-5/}
}