TY  - RPRT
TI  - An empirical assessment of refraction error in leveling as a function of survey order and environment
AU  - Robert O. Castle
AU  - Robert K. Mark
AU  - Roger H. Shaw
PY  - 1994
DO  - 10.3133/b2114
UR  - https://pubs.usgs.gov/publication/b2114
ID  - b2114
ER  -