Van Zyl, J. E. <br/><br/>
Unveiling the universe  an introduction to astronomy 
J. E. van Zyl 
 - London  Springer-Verlag  1996 
 - 324 p. : ill. ; 25 cm. 
<br/><br/>p. 315-316. 
<br/><br/><label>ISBN: </label>3540760237  RM128.24 
<br/><br/><label>LCCN: </label>96-13944 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Astronomy