TY  - RPRT
TI  - Multispectral techniques for general geological surveys - evaluation of a four-band photographic system
AU  - D. F. Crowder
PY  - 1969
DO  - 10.3133/ofr6964
UR  - https://pubs.usgs.gov/publication/ofr6964
ID  - ofr6964
ER  -