Durkin, John. <br/><br/>
Vertical magnetic noise in the voice frequency band within and above coal mines / 
by John Durkin. 
 - [Washington, D.C.] :  U.S. Dept. of the Interior, Bureau of Mines,  1983. 
 - 27 p. :  ill. ;  28 cm. 
 - Report of investigations ;  8828 .
 - Report of investigations (United States. Bureau of Mines) ;  8828. .
<br/><br/>Bibliography: p. 21-22. 
<br/><br/><label>LCCN: </label>83600164  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Coal mines and mining--Communication systems.<br/>Electromagnetic noise.<br/>Voice frequency.
<br/><br/><label>LC Class. No.: </label>TN23  TN344  / .U43 no. 8828 
<br/><br/><label>Dewey Class. No.: </label>622 s  622 
<br/><br/><label>Gov. Doc. Class. No.: </label>I 28.23:8828.