Walker, R. C.  1896- <br/><br/>
Photoelectric cells in industry / 
R. C. Walker 
 - London :  Sir ISAAC Pitman,  1948 
 - x, 517 p. :  ill. ;  23 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Photoelectric cells<br/>Electronic apparatus and appliances