TY  - BOOK
AU  - 
TI  - The Economic Definition Of Ore : Cut-Off Grades In Theory And Practice
SN  - 0900117451
U1  - 557.3 LAN 1st.ed.
PY  - 1988///
CY  - London
PB  - Mining Journal Books Limited
KW  - Ore
KW  - Earth Sciences of North America
N1  - Includes bibliographical references ( p.: 146 - 149 )
ER  -