Bieniawski, Z. T. <br/><br/>
Engineering rock mass classifications :  a complete manual for engineers and geologists in mining, civil, and petroleum engineering / 
Z. T. Bieniawski 
 - New York :  John Wiley & Sons,  1989 
 - 251 p. ;  24 cm. 
<br/><br/> 'A Wiley-Interscience publication.'  Includes index 
<br/><br/><label>ISBN: </label>0471601721 
<br/><br/><label>LCCN: </label>89-030956 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geology, Economic<br/>Rocks--Classification<br/>Rock mechanics