TY  - RPRT
TI  - Ground-based upward extrapolated gravity data for use in testing the aerial profiling of terrain system (APTS)
AU  - T.G. Hildenbrand
AU  - R.P. Kucks
AU  - W. F. Hanna
PY  - 1984
DO  - 10.3133/ofr84775
UR  - https://pubs.usgs.gov/publication/ofr84775
ID  - ofr84775
ER  -