Some OPAL libraries remain closed or are operating at reduced service levels. Materials from those libraries may not be requestable; requested items may take longer to arrive. Note that pickup procedures may differ between libraries. Please contact your library for new procedures, specific requests, or other assistance.
Your session will expire automatically in 0 seconds.
American Ephemeris And Nautical Almanac Supplement : Explanatory supplement to the astronomical ephemeris and the American ephemeris and nautical almanac / prepared jointly by the Nautical Almanac offices of the United Kingdom and the United States of America.