@article{TAC_2021_36_a12,
     author = {Susan Niefield},
     title = {Extensions and {Glueing} in {Double} {Categories}},
     journal = {Theory and applications of categories},
     pages = {348--367},
     publisher = {mathdoc},
     volume = {36},
     year = {2021},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2021_36_a12/}
}