Hearing and Seeing / 
John A. Clark...[et al] 
 - Britain :  Longmans company,  1956. 
 - 80 p. :  ill. ;  20 cm. 
 - Science on the March  Unit 7 .
<br/><br/>392  392 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Technological science --India--Heering
<br/><br/><label>Dewey Class. No.: </label>617.8 / C13h