TY  - RPRT
TI  - The upper Mississippi Valley zinc-lead district; In two parts: I General structural relations of the upper Mississippi Valley zinc-lead district. II. The ore deposits of the upper Mississippi Valley zinc-lead district
AU  - Allen V. Heyl
PY  - 1950
DO  - 10.3133/ofr5013
UR  - https://pubs.usgs.gov/publication/ofr5013
ID  - ofr5013
ER  -