TY  - RPRT
TI  - Geothermal energy: clean power from the Earth's heat
AU  - Wendell A. Duffield
AU  - John H. Sass
PY  - 2003
DO  - 10.3133/cir1249
UR  - https://pubs.usgs.gov/publication/cir1249
ID  - cir1249
ER  -