Al'pert, Yakov L. <br/><br/>
Propagation of ELF and VLF waves near the earth   
by Yakov L. Al'pert, Dora S. Fligel 
 - New York  Consultants Bureau  1970 
 - v, 171p. 
<br/><br/><label>LCCN: </label>69-12526 
<br/><br/><label>Dewey Class. No.: </label>621.384153  / N70