@article{2194,
author = {Specker, Ernst},
title = {Additive Gruppen von Folgen ganzer Zahlen},
journal = {Portugaliae mathematica},
volume = {9},
year = {1950},
pages = {131-140},
zbl = {0041.36314},
mrnumber = {0039719},
language = {en},
url = {http://dml.mathdoc.fr/item/2194}
}
Specker, Ernst. Additive Gruppen von Folgen ganzer Zahlen. Portugaliae mathematica, Tome 9 (1950) pp. 131-140. http://gdmltest.u-ga.fr/item/2194/