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.

Mode of access: Internet.

The Year-book of Wireless Telegraphy & Telephony

Mode of access: Internet.