TY  - RPRT
TI  - What is in a contour map? A region-based logical formalization of contour semantics
AU  - E. Lynn Usery
AU  - Torsten Hahmann
PY  - 2015
DO  - 10.1007/978-3-319-23374-1_18
UR  - https://pubs.usgs.gov/publication/70159738
ID  - 70159738
ER  -