@article{05934774,
title = {Covariant presheaves and subalgebras.},
journal = {Theory and Applications of Categories [electronic only]},
volume = {25},
year = {2011},
pages = {342-367},
zbl = {1230.06008},
language = {en},
url = {http://dml.mathdoc.fr/item/05934774}
}
Höhle, Ulrich. Covariant presheaves and subalgebras.. Theory and Applications of Categories [electronic only], Tome 25 (2011) pp. 342-367. http://gdmltest.u-ga.fr/item/05934774/