Steward, G. C. <br/><br/>
The symmetrical optical system / 
by G. C. Steward 
 - London :  The University Press,  1928 
 - viii, 102 p. ;  22 cm. 
 - Cambridge tracts in mathematics and mathematical physics ;  no. 25 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Optics