Genre
Maps
1,662
Bibliographies
190
Databases
175
Conference papers and proceedings
170
Statistics
128
Topographic maps
126
Periodicals
119
Geological maps
75
Handbooks and manuals
73
Technical reports
73
Remote-sensing maps
61
Congresses
46
Catalogs
37
Serial publications
35
Academic theses
30
Bathymetric maps
30
Drawings
27
Guidebooks
25
Graphs
19
Geographic information systems
17
Software
16
Remote-sensing images
15
Atlases
9
Directories
8
Dictionaries
7
Fiction
7
Observations
7
Indexes
5
Pictures
5
Abstracts
4
Aerial photographs
4
Electronic government information United States
4
Illustrated works
4
Photographs
4
Relief models
4
Tables (Data)
4
Classification
3
Digital maps
3
Registers (Lists)
3
Annual reports
2
Case studies
2
Charts, diagrams, etc
2
Electronic government information
2
Geological cross-sections
2
Laboratory manuals
2
Physical maps
2
Posters
2
Quadrangle maps
2
Surveys
2
Video recordings
2
more ...