Reference

	Astronomical Methods and Calculations by A. Acker, C. Jaschek, C. Kitchin Year: 1986 Hits: 4876 Date insert: Monday, 31 December 2018
	Astronomical Sketching: A Step-by-Step Introduction by Richard Handy, David B. Moody, Jeremy Perez, Erika Rix, Sol Robbins Year: 2007 Hits: 7785 Date insert: Monday, 31 December 2018
	Astronomy Manual The Practical Guide to the Night Sky by Jane A. Green Year: 2010 Hits: 2810 Date insert: Monday, 31 December 2018
	Astronomy: A Self-Teaching Guide, Fifth Edition by Dinah L. Moché Hits: 2008 Date insert: Monday, 31 December 2018
	Binocular Highlights by Gary Seronik Year: 2013 Hits: 4590 Date insert: Monday, 31 December 2018