Urban, S. E., & Seidelmann, P. K. (2013). Explanatory supplement to the Astronomical almanac (3rd ed.). University Science Books.
Chicago Edition CitationUrban, Sean E., i P. Kenneth Seidelmann. Explanatory Supplement to the Astronomical Almanac. 3rd ed. Mill Valley, Calif.: University Science Books, 2013.
Cita MLAUrban, Sean E., i P. Kenneth Seidelmann. Explanatory Supplement to the Astronomical Almanac. 3rd ed. University Science Books, 2013.
Atenció: Aquestes cites poden no estar 100% correctes.