Genre
Maps
354
Bibliographies
25
Guidebooks
14
Conference papers and proceedings
10
Databases
9
Abstracts
2
Geological maps
2
Periodicals
2
Quadrangle maps
2
Surveys
2
Technical reports
2
Biographies
1
Controlled vocabularies
1
Dictionaries
1
Electronic government information United States
1
Geographic information systems
1
Geological cross-sections
1
Index maps
1
Physical maps
1
Pictures
1
Programmed instructional materials
1