APA (7th ed.) Citation

United States. Radio Service. (1916). Important events in radiotelegraphy. U.S. Government Printing Office.

Chicago Style (17th ed.) Citation

United States. Radio Service. Important Events in Radiotelegraphy. [Washington?]: U.S. Government Printing Office, 1916.

MLA (9th ed.) Citation

United States. Radio Service. Important Events in Radiotelegraphy. U.S. Government Printing Office, 1916.

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