Moebs, Noel N. <br/><br/>
Subsidence over four room-and-pillar sections in southwestern Pennsylvania / 
by Noel N. Moebs. 
 - Washington, D.C. :  U.S. Dept. of the Interior, Bureau of Mines,  1982. 
 - 23 p. :  ill. ;  28 cm. 
 - Report of investigations  8645 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mine subsidence--Measurement.--Pennsylvania<br/>Coal mines and mining--Safety measures.--Pennsylvania
<br/><br/><label>Dewey Class. No.: </label>622.8