@article{TAC_2004_12_a4,
     author = {Panagis Karazeris},
     title = {Notions of flatness relative to a {Grothendieck} topology},
     journal = {Theory and applications of categories},
     pages = {225--236},
     year = {2004},
     volume = {12},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2004_12_a4/}
}