@article{CLTM_1997_1997_1_a58,
     author = {Urbanski, Ryszard},
     title = {Pares de conjuntos con uni\'on convexa.},
     journal = {Collectanea mathematica},
     pages = {791-798},
     publisher = {mathdoc},
     volume = {48},
     number = {4-5-6},
     year = {1997},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CLTM_1997_1997_1_a58/}
}