Roy, A. E.  1924- <br/><br/>
Astronomy :  principles and practice / 
A.E. Roy, D. Clarke 
 - 2nd ed. 
 - Bristol :  Hilger,  1982 
 - xv, 342 p. :  ill. ;  28 cm. 
<br/><br/>Includes index 
<br/><br/><label>ISBN: </label>0852744633 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Astronomy