@article{10_1017_S0017089518000320,
     author = {SANTIAGO, VALENTE},
     title = {STRATIFYING {SYSTEMS} {FOR} {EXACT} {CATEGORIES}},
     journal = {Glasgow mathematical journal},
     pages = {501--521},
     year = {2019},
     volume = {61},
     number = {3},
     doi = {10.1017/S0017089518000320},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089518000320/}
}