Não informado. (1950). British National Bibliography. British Library, Bibliographic Services Division.
Chicago-viite (17. p.)Não informado. British National Bibliography. London: British Library, Bibliographic Services Division, 1950.
MLA-viite (8. p.)Não informado. British National Bibliography. British Library, Bibliographic Services Division, 1950.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.