Format
Book
2,632,516
Conference Proceeding
38,352
Journal
38,076
Serial
32,658
Electronic
27,746
Thesis
25,702
Government Document
20,704
Unknown
20,355
Audio
4,143
Map
3,780
Photo
2,729
Book Chapter
2,146
Newspaper
1,699
Manuscript
1,429
Kit
983
Reference Material
916
Musical Score
215
Physical Object
33
Article
17