TY  - RPRT
TI  - 20th century U.S. mineral prices decline in constant dollars
AU  - Daniel E. Sullivan
AU  - John L. Sznopek
AU  - Lorie A. Wagner
PY  - 2000
DO  - 10.3133/ofr00389
UR  - https://pubs.usgs.gov/publication/ofr00389
ID  - ofr00389
ER  -