@article{TAC_2012_27_a6,
     author = {Michael Shulman},
     title = {Exact completions and small sheaves},
     journal = {Theory and applications of categories},
     pages = {97--173},
     publisher = {mathdoc},
     volume = {27},
     year = {2012},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2012_27_a6/}
}