Wagner, Lorie A. <br/><br/>
Materials in the economy:  materials flows, scarcity, and the environment / 
Lorie A. Wagner 
 - Washington :  U.S. G.P.O.,  2001 
 - iv, 29 p. :  ill. (some colour0 maps ;  2001 
 - U.S. Geological Survey Circular;  no.1221 .
<br/><br/>Refrences: p.28-29 
<br/><br/><label>ISBN: </label>0607984120