@article{TAC_2022_38_a22,
     author = {Jason Parker},
     title = {Extensivity of categories of relational structures},
     journal = {Theory and applications of categories},
     pages = {898--912},
     publisher = {mathdoc},
     volume = {38},
     year = {2022},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2022_38_a22/}
}