Genre
Maps
3,282
Databases
507
Periodicals
248
Statistics
235
Remote-sensing maps
134
Topographic maps
128
Maps, Topographic
102
Bibliography
79
Congresses
72
Geological maps
72
Bathymetric maps
58
Electronic journals
41
Charts, diagrams, etc
36
Remote-sensing images
36
Software
30
Handbooks, manuals, etc
25
Observations
24
Academic theses
20
Photographs
17
Guidebooks
11
Nomenclature
9
Classification
8
Pictorial works
8
Directories
7
Catalogs
6
Internet resources
6
Census, 2000
5
Computer programs
5
Electronic government information
5
Relief models
5
Slides
5
Aerial photographs
4
Electronic books
4
Digital maps
3
Drawings
3
Index maps
3
Indexes
3
Physical maps
3
Posters
3
Aerial views
2
CD-ROM
2
Case studies
2
Census data
2
Chronology
2
Environmental impact statements
2
Gazetteers
2
Geographic information systems
2
Geographic information systems data
2
Geospatial data
2
Gravity anomaly maps
2
more ...