@article{10_4153_CJM_1990_012_x,
     author = {B\"orger, Reinhard and Tholen, Walter},
     title = {Total {Categories} and {Solid} {Functors}},
     journal = {Canadian journal of mathematics},
     pages = {213--229},
     year = {1990},
     volume = {42},
     number = {2},
     doi = {10.4153/CJM-1990-012-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1990-012-x/}
}