Admiralty list of radio signals : pilot services, vessel traffic services and port operations North East Asia. - United Kingdom : The United Kingdom Hydrographic Office , 2011 - xxvi, 298 pages, volume 6 : color maps ; 30 cm. Includes Index. ISBN: 9780707719382 Subjects--Topical Terms: Radio SignalsMarine Navigation. Dewey Class. No.: 623.8932 / A1