@article{TAC_2014_29_a28,
     author = {Dorette A. Pronk and Michael A. Warren},
     title = {Bicategorical fibration structures and stacks},
     journal = {Theory and applications of categories},
     pages = {836--873},
     publisher = {mathdoc},
     volume = {29},
     year = {2014},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2014_29_a28/}
}