TY  - RPRT
TI  - Hand signs for technical terms used in thematic and topographic mapping
AU  - Richard W. Will
AU  - William B. Krohn
PY  - 1989
DO  - 10.3133/cir1014
UR  - https://pubs.usgs.gov/publication/cir1014
ID  - cir1014
ER  -