Kertis, Carla A. <br/><br/>
Reducing hazards in underground coal mines through the recognition and delineation of coalbed discontinuities caused by ancient channel processes / 
by Carla A. Kertis. 
 - Pittsburgh, Pa. :  U.S. Dept. of the Interior, Bureau of Mines,  1985. 
 - 23 p. :  ill., maps ;  28 cm. 
 - Report of investigations ;  8987 .
 - Report of investigations (United States. Bureau of Mines) ;  8987. .
<br/><br/>Bibliography: p. 21-23. 
<br/><br/><label>LCCN: </label>85600080  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Coal--Geology--Pennsylvania--Indiana County.<br/>Coal--Geology--Pennsylvania--Armstrong County.<br/>River channels.<br/>Coal mines and mining--Safety measures.--Pennsylvania--Indiana County<br/>Coal mines and mining--Safety measures.--Pennsylvania--Armstrong County
<br/><br/><label>LC Class. No.: </label>TN23  TN805.P4  / .U43 no. 8987 
<br/><br/><label>Dewey Class. No.: </label>622 s  622/.334 
<br/><br/><label>Gov. Doc. Class. No.: </label>I 28.23:8987