TY  - RPRT
TI  - Map showing engineering aspects of karst in the United States
AU  - W.E. Davies
AU  - J.H. Simpson
AU  - G.C. Ohlmacher
AU  - W.S. Kirk
AU  - E.G. Newton
PY  - 1976
DO  - 10.3133/ofr76623
UR  - https://pubs.usgs.gov/publication/ofr76623
ID  - ofr76623
ER  -