Não informado. (1920). Discovery: The magazine of scientific progress. Professional and Industrial Publishing.
Chicago-referens (17:e uppl.)Não informado. Discovery: The Magazine of Scientific Progress. London: Professional and Industrial Publishing, 1920.
MLA-referens (8:e uppl.)Não informado. Discovery: The Magazine of Scientific Progress. Professional and Industrial Publishing, 1920.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.