@article{PORMA_1965__24_4_114966,
     author = {Morgado, Jos\'e},
     title = {Note on the system of closure operators of the ordinal product of partially ordered sets},
     journal = {Portugaliae mathematica},
     pages = {189--195},
     publisher = {mathdoc},
     volume = {24},
     number = {4},
     year = {1965},
     mrnumber = {0210626},
     zbl = {0158.27001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1965__24_4_114966/}
}