APA (7th ed.) Citation

ProQuest (Firm). (1947). Safety in air navigation. [publisher not identified].

Chicago Style (17th ed.) Citation

ProQuest (Firm). Safety in Air Navigation. Washington: [publisher not identified], 1947.

MLA (9th ed.) Citation

ProQuest (Firm). Safety in Air Navigation. [publisher not identified], 1947.

Warning: These citations may not always be 100% accurate.