Scherf, David. <br/><br/>
Clinical electrocardiography / 
by David Scherf and Linn J. Boyd. 
 - 4th ed. 
 - Philadelphia :  J.B. Lippincott Company,  [1946] 
 - xii, 267 p.  illus., diagrs.  27 cm. 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Electrocardiography.