@article{TAC_2012_27_a13,
     author = {Maria Manuel Clementino and Walter Tholen},
     title = {Proper maps for lax algebras and the {Kuratowski-Mr\'owka} theorem},
     journal = {Theory and applications of categories},
     pages = {327--346},
     publisher = {mathdoc},
     volume = {27},
     year = {2012},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TAC_2012_27_a13/}
}