Twisselmann, L <br/><br/>
[Stages in the development of instruments for determining subjective refraction].  [electronic resource] 

 -  Klinische Monatsblatter fur Augenheilkunde  Jan 1991 
 - 59-63 p.  digital 
<br/><br/> Publication Type: English Abstract; Historical Article; Journal Article 
<br/><br/><label>ISSN: </label>0023-2165 
<br/><br/><label>Standard No.: </label>10.1055/s-2008-1045931  doi 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Eyeglasses--history<br/>Germany<br/>History, 20th Century<br/>Humans<br/>Ophthalmology--history<br/>Refraction, Ocular