TY  - RPRT
TI  - Twenty-First Annual report of the Director of the United States Geological Survey, 1899-1900: Part III - General geology. Ore and phosphate deposits, Philippines
AU  - Charles D. Walcott
PY  - 1901
DO  - 10.3133/ar21_3
UR  - https://pubs.usgs.gov/publication/ar21_3
ID  - ar21_3
ER  -