Não informado. (1940). Engineers digest: Review of engineering progress. Engineer's Digest Publications.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিNão informado. Engineers Digest: Review of Engineering Progress. London: Engineer's Digest Publications, 1940.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিNão informado. Engineers Digest: Review of Engineering Progress. Engineer's Digest Publications, 1940.
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