Format
Book
2,633,694
Conference Proceeding
38,375
Journal
38,091
Serial
32,664
Electronic
27,749
Thesis
25,708
Government Document
20,712
Unknown
20,357
Audio
4,144
Map
3,780
Photo
2,732
Book Chapter
2,146
Newspaper
1,699
Manuscript
1,431
Kit
983
Reference Material
913
Musical Score
215
Physical Object
33
Article
17