Quotients by groupoids. Keel, S. & Mori, S. Ann. of Math. (2), 145(1):193–213, 1997.
doi  bibtex   
@Article{	  kee.mor:97,
  author	= {Keel, Se{\'a}n and Mori, Shigefumi},
  doi		= {10.2307/2951828},
  fjournal	= {Annals of Mathematics. Second Series},
  issn		= {0003-486X},
  journal	= {Ann. of Math. (2)},
  number	= 1,
  pages		= {193--213},
  title		= {Quotients by groupoids},
  volume	= 145,
  year		= 1997,
  bdsk-url-1	= {http://dx.doi.org/10.2307/2951828}
}

Downloads: 0