United States. Bureau of Foreign and Domestic Commerce. (1927). Beam, or directional, system of short-wave radiotelegraphy. GPO.
Chicago Style (17th ed.) CitationUnited States. Bureau of Foreign and Domestic Commerce. Beam, or Directional, System of Short-wave Radiotelegraphy. [Washington]: GPO, 1927.
MLA (9th ed.) CitationUnited States. Bureau of Foreign and Domestic Commerce. Beam, or Directional, System of Short-wave Radiotelegraphy. GPO, 1927.
Warning: These citations may not always be 100% accurate.