Genre
Indexes
Sources
188
History
161
Periodicals
149
Bibliography
97
Index
68
Bibliographies
50
indexes (reference sources)
47
Catalogs
36
Electronic books
28
Microform catalogs
20
Archives
15
Dictionaries
15
Biographies
13
Databases
10
Biography
8
CD-ROMs
7
Government publications
7
Abstracts
6
Chronology
6
Tables of contents
6
Correspondence
5
Diaries
5
Digests
5
Online databases
5
Concordances
4
Early works to 1800
4
Electronic reference sources
4
bibliographies
4
Bibliographie
3
Catalogues
3
Collections
3
Congresses
3
Directories
3
Early works
3
Imprints
3
Périodiques
3
Périodiques
3
Statutes and codes
3
Bibliographies (form)
2
Chronologies
2
Committees
2
Criticism, interpretation, etc
2
Electronic journals
2
Facsimiles
2
Handbooks, manuals, etc
2
Indexes (reference sources)
2
Journaux intimes
2
Periodical
2
Personal correspondence
2
more ...