Ridley, B. K..
Time, space and things /
B.K. Ridley 
. - Harmondsworth : Penguin Books,  1980 
. - 169 p.  ill., tab., schem.  19 cm. 
 - (Pelican Books  Science : Physics )
<br/><label>  ISBN: </label>0-14-02-2332-0