@article{PORMA_1950__9_3_114684,
     author = {Specker, Ernst},
     title = {Additive {Gruppen} von {Folgen} ganzer {Zahlen}},
     journal = {Portugaliae mathematica},
     pages = {131--140},
     publisher = {mathdoc},
     volume = {9},
     number = {3},
     year = {1950},
     mrnumber = {0039719},
     zbl = {0041.36314},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1950__9_3_114684/}
}