@article{PORMA_1992__49_4_115797,
     author = {Nachbin, Leopoldo},
     title = {Compact unions of closed subsets are closed and compact intersections of open subsets are open},
     journal = {Portugaliae mathematica},
     pages = {403--409},
     publisher = {mathdoc},
     volume = {49},
     number = {4},
     year = {1992},
     mrnumber = {1300574},
     zbl = {0784.54002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1992__49_4_115797/}
}