Genre
Maps
3,373
Bibliographies
109
Databases
44
Graphs
39
Charts, diagrams, etc
34
Geological maps
29
Indexes
29
Conference papers and proceedings
26
Guidebooks
25
Nomenclature
14
Bathymetric maps
11
Catalogs
11
Drawings
11
Index maps
11
Topographic maps
11
Physical maps
10
Academic theses
8
Periodicals
8
Quadrangle maps
8
Geological cross-sections
6
Remote-sensing maps
6
Congresses
5
Technical reports
5
Atlases
4
Remote-sensing images
3
Abstracts
2
Digital maps
2
Pictures
2
Aerial views
1
Controlled vocabularies
1
Dictionaries
1
Electronic government information United States
1
Geographic information systems
1
Geospatial data
1
Illustrated works
1
Literature
1
Posters
1
Programmed instructional materials
1
Raster data
1
Serial publications
1
Statistics
1
Vector data
1