TY  - RPRT
TI  - Maps showing platinum-group-element occurrences in the conterminous United States, updated as of 1993
AU  - J.A. Peterson
PY  - 1994
DO  - 10.3133/mf2270
UR  - https://pubs.usgs.gov/publication/mf2270
ID  - mf2270
ER  -