Cashell, G. T. Willoughby <br/><br/>
Handbook of orthoptic principles 
By G. T. Willoughby Cashell, Isobel M. Durran ; assisted by A. V. MacLellan foreword by T. Keith Lyle 
 - 4th ed. 
 - Edinburgh  Churchill Livingstone  1980 
 - 168 p. :  22 cm. 
<br/><br/><label>ISBN: </label>0443022003 
<br/><br/><label>LCCN: </label>80-040527 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Orthoptics