APA (7th ed.) Citation

United States. Block Signal and Train Control Board. (1909). Block signals on railroads of U.S., Jan. 1, 1909. GPO.

Chicago Style (17th ed.) Citation

United States. Block Signal and Train Control Board. Block Signals on Railroads of U.S., Jan. 1, 1909. [Washington]: GPO, 1909.

MLA (9th ed.) Citation

United States. Block Signal and Train Control Board. Block Signals on Railroads of U.S., Jan. 1, 1909. GPO, 1909.

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