The United States Naval Observatory Nautical Almanac Office. text Washington, D.C London U.S. Nautical Almanac Office in the United States (USNO) Her majesty's Nautical Almanac Office (HMNAO) in the United Kingdom monographic Nautical almanacs D 213.8/4: D 213.8/4: http://purl.access.gpo.gov/GPO/LPS49630 http://purl.access.gpo.gov/GPO/LPS49630 20160527183811.0 300341