Não informado. (1950). British National Bibliography. British Library, Bibliographic Services Division.
Chicago-referens (17:e uppl.)Não informado. British National Bibliography. London: British Library, Bibliographic Services Division, 1950.
MLA-referens (8:e uppl.)Não informado. British National Bibliography. British Library, Bibliographic Services Division, 1950.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.