星際彗星Space.com. 2007-12-24 [2008-12-30]. (原始内容存档于2010-09-17). Struve, Otto; Lynds, Beverly; Pillans, Helen. Elementary Astronomy. New York: Oxford University Press
武仙座Yuán,Heavenly Market enclosure)。 Ridpath & Tirion 2001,第154-156頁. Struve, Otto; Lynds, Beverly and Pillans, Helen. Elementary Astronomy. New York: Oxford University