(1955). The American ephemeris and nautical almanac for the year 1957. Washington: U.S. Government Printing Office.
Παραπομπή Chicago StyleThe American Ephemeris and Nautical Almanac for the Year 1957. Washington: U.S. Government Printing Office, 1955.
Παραπομπή MLAThe American Ephemeris and Nautical Almanac for the Year 1957. Washington: U.S. Government Printing Office, 1955.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.