Direct current and magnetism / 
Edited.Edgar J Black 
 - Lodon.:  Iliffe book ltd,  c1964. 
 - 119 p.  22 cm. 
<br/><br/>
<br/><br/><br/>English. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Direct current.
<br/><br/><label>Dewey Class. No.: </label>621.3/BLD