Não informado. (1940). Engineers digest: Review of engineering progress. Engineer's Digest Publications.
Chicago-viite (17. p.)Não informado. Engineers Digest: Review of Engineering Progress. London: Engineer's Digest Publications, 1940.
MLA-viite (8. p.)Não informado. Engineers Digest: Review of Engineering Progress. Engineer's Digest Publications, 1940.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.