Statistical analysis of coal mine accidents in Pennsylvania, 1916 to 1922 inclusive. 

 - Harrisburg  [1924] 
 - 140 p.  diagrs.  24 cm. 
<br/><br/><label>LCCN: </label>l  24000126  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Coal mine accidents.<br/>Coal mines and mining--Pennsylvania.
<br/><br/><label>LC Class. No.: </label>HD7269  / .M61 U645