Gaya APA

Urban, S, E., Seidelmann, P, K. (2013). Explanatory supplement to the astronomical al manac (3rd ed. /). California: University Sciene Books.

Gaya MLA

Urban, Sean, E.., Seidelmann, P., Kenneth.. "Explanatory supplement to the astronomical al manac". 3rd ed. / California: University Sciene Books, 2013. Buku.