@article{CLTM_1991_1991_1_a18,
     author = {D{\'\i}az, Santiago},
     title = {Completitud {\ensuremath{\Sigma}} y teoremas de grafos cerrados.},
     journal = {Collectanea mathematica},
     pages = {253-263},
     publisher = {mathdoc},
     volume = {42},
     number = {3},
     year = {1991},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CLTM_1991_1991_1_a18/}
}