@article{PORMA_1963__22_4_114906,
     author = {Hammer, Preston C.},
     title = {Extended topology: connected sets and {Wallace} separations},
     journal = {Portugaliae mathematica},
     pages = {167--187},
     publisher = {mathdoc},
     volume = {22},
     number = {4},
     year = {1963},
     mrnumber = {0221457},
     zbl = {0137.15601},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1963__22_4_114906/}
}