Stone, Ralph W.  1876-1964. <br/><br/>
Pennsylvania caves, 
by Ralph W. Stone. 
 - Harrisburg,  Department of internal affairs, Topographic and geologic survey,  1930. 
 - 63 p. incl. illus., maps.  23 cm. 
 - Pennsylvania. Geological survey (4th, 1919-  ) Bulletin G3 .
 - Bulletin G,  3. .
<br/><br/>Bibliographical footnotes. 
<br/><br/><label>LCCN: </label>gs 30000221  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Caves.
<br/><br/><label>LC Class. No.: </label>GB605.P4  / S7 
<br/><br/><label>Gov. Doc. Class. No.: </label>PY G345/4.3 G3