Reference

	Summer Stargazing: A Practical Guide for Recreational Astronomers by Alan Dressler, W. Schlosser Year: 2005 Hits: 3805 Date insert: Monday, 31 December 2018
	The 20-cm Schmidt-Cassegrain Telescope: A Practical Observing Guide by Peter I. Manly Year: 1999 Hits: 3913 Date insert: Monday, 31 December 2018
	The Astronomy Encyclopedia by Kevin Krisciunas, Jay M Pasachoff Year: 2002 Hits: 3925 Date insert: Monday, 31 December 2018
	THE BACKYARD ASTRONOMERS GUIDE by Terence Dickenson, Alan Dyer Year: 2008 Hits: 2669 Date insert: Monday, 31 December 2018
	The Beginner's Observing Guide by Leo Enright Year: 2003 Hits: 1685 Date insert: Friday, 12 May 2023