Summen von $ℵ_1$ Mengen

Instytut Matematyczny Polskiej Akademii Nauk / Institute of Mathematics / Publishing house / Journals and Serials / Fundamenta Mathematicae / All issues

Felix Hausdorff Fundamenta Mathematicae 26 (1936), 241-255 DOI: 10.4064/fm-26-1-241-255