TY  - RPRT
TI  - Eighteenth annual report of the United States Geological Survey to the Secretary of the Interior, 1896-1897: Part I - Director's report, including triangulation and spirit leveling
AU  - Charles D. Walcott
PY  - 1897
DO  - 10.3133/ar18_1
UR  - https://pubs.usgs.gov/publication/ar18_1
ID  - ar18_1
ER  -