1. [Ordnance pamphlet] OP (series). 1303. United States Navy synchros, description and operations; [Apr. 15, 1958], 1st revision. Bookmark Corporate/Agency Authors: Old-Age and Survivors Insurance Bureau and Health, Education and Welfare Dept. Publisher: Old-Age and Survivors Insurance Bureau Date: [1958.] SuDoc number: D 215.9:1303