books.google.nl - The Explanatory Supplement provides a detailed description of how to perform practical astronomy or spherical astronomy. This completely revised and rewritten edition is an authoritative source on astronomical phenomena and calendars. Although this paperback edition carries a 2006 copyright date, it...http://books.google.nl/books/about/Explanatory_Supplement_to_the_Astronomic.html?hl=nl&id=uJ4JhGJANb4C&utm_source=gb-gplus-shareExplanatory Supplement to the Astronomical Almanac
