Proctor, Robert V.  1890-1967. <br/><br/>
Rock tunneling with steel supports /  
by Robert V. Proctor ... Thomas L. White ... with an Introduction to tunnel geology, by Karl Terzaghi. 
 - Ohio:   [Commercial Shearing & Stamping Co.],  1946. 
 - 271 p.  illus., diagrs.  28 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>TUNELES<br/>ROCAS<br/>EXCAVACIONES
<br/><br/><label>Universal Decimal Class. No.: </label>622.14