Wallenfels, Herman G. <br/><br/>
Hearing aids on prescription, 
by Herman G. Wallenfels. With an introd. by John A. T. Ross. 
 - Springfield, Ill.,  Thomas  [1967] 
 - xv, 109 p.  illus.  24 cm. 
<br/><br/>Bibliography: p. 109. 
<br/><br/><label>LCCN: </label>67012046  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Hearing aids.
<br/><br/><label>LC Class. No.: </label>RF300  / .W3 
<br/><br/><label>Dewey Class. No.: </label>617.89 WAL