The Stacks project

@ARTICLE{Spivakovsky,
    AUTHOR = "Spivakovsky, Mark",
    TITLE = "A new proof of {D}. {P}opescu's theorem on smoothing of ring homomorphisms",
    JOURNAL = "J. Amer. Math. Soc.",
    FJOURNAL = "Journal of the American Mathematical Society",
    VOLUME = "12",
    YEAR = "1999",
    NUMBER = "2",
    PAGES = "381--444",
    URL = "https://dx.doi.org/10.1090/S0894-0347-99-00294-5"
}