International Wireless Telegraphy: Hearing Before the Committee on Foreign Relations, United States Senate, Sixty-second Congress, on an International Wireless Telegraphy Convention, with Service Regulations Annexed Thereto, a Supplementary Agreement, and a Final Protocol, All Signed at Berlin on November 3, 1906, by Delegates of the United States and Those of Several Other Powers. February 21, 1912
United States. Congress. Senate. Committee on Foreign Relations