Abell, George Ogden, 1927- <br/><br/>
Exploration of the universe / 
George O. Abell, David Morrison, Sidney C. Wolff. 
 - 6th ed. 
 - Philadelphia :  Saunders College Pub,  1993. 
 - xiv, 681 p. : figs., tables 
<br/><br/> Includes appendices and index 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Astronomy