Watson, Leland A.  1907-1960. <br/><br/>
Hearing tests and hearing instruments/ 
by Leland A. Watson and Thomas Tolan. 
 - Baltimore,  Williams & Wilkins Co.,  1949. 
 - x, 597 p.  illus.  24 cm. 
<br/><br/>Bibliography: p. 521-568. 
<br/><br/><label>LCCN: </label>49048554  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Audiometry.<br/>Hearing aids.
<br/><br/><label>LC Class. No.: </label>RF151  / .W18 
<br/><br/><label>Dewey Class. No.: </label>617.89 WAT 
<br/><br/><label>National Library of Medicine Call No.: </label>WV272  / .W339h 1949