Abhandlungen aus dem Mathematischen Seminar der Universität HamburgDecember 1931, Volume 8, Issue 1, pp 307–314 | Cite asZu einer Arbeit von 0. schreierAuthorsAuthors and affiliationsWitold HurewiczArticle 17 Downloads 3 Citations This is a preview of subscription content, log in to check access.PreviewUnable to display preview. Download preview PDF.Unable to display preview. Download preview PDF.Copyright information© Mathematische Seminar 1931Authors and AffiliationsWitold Hurewicz11.Amsterdam