Media type: E-Article Title: 4387 Contributor: Bateman, Paul Published: Informa UK Limited, 1951 Published in: The American Mathematical Monthly, 58 (1951) 9, Seite 638 Language: Without Specification DOI: 10.2307/2306371 ISSN: 0002-9890 Keywords: General Mathematics Origination: Footnote: Access State: Open Access