Machholz, Don. <br/><br/>
The Observing Guide to the Messier Marathon  A Handbook and Atlas /  [electronic resource] : 
Don Machholz. 
 - Cambridge :  The University Press,  2012 
 - 1 online resource (172 p.) 
<br/><br/>Includes bibliographic references and index 
<br/><br/><label>ISBN: </label>9780511536458 (ebook) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Astronomy--Observers' manuals