TY  - RPRT
TI  - Preliminary digital geologic map of the Penokean (early Proterozoic) continental margin in northern Michigan and Wisconsin
AU  - W.F. Cannon
AU  - Doug Ottke
PY  - 1999
DO  - 10.3133/ofr99547
UR  - https://pubs.usgs.gov/publication/ofr99547
ID  - ofr99547
ER  -