The 1931 international code of signals for the use of all nations :
effective January 1, 1934 ...
APA Citation
United States. Hydrographic Office. (1937). The 1931 international code of signals for the use of all nations: effective January 1, 1934 ... Washington: U.S. G.P.O. .
MLA Citation
United States. Hydrographic Office. The 1931 International Code of Signals for the Use of All Nations: Effective January 1, 1934 ... Washington: U.S. G.P.O. , 1937.
Warning: These citations may not always be complete (especially for serials).