Operas 52,517
Orchestral music 16,145
Ouvrages illustrés 14,583
Outlines, syllabi, etc 14,031
Ouvrages avant 1800 11,679
Observations 10,925
Oral histories (literary works) 10,857
Oral histories 9,739
Organ music 8,565
Outlines and syllabi 8,406
Overtures 7,723
Oratorios 5,893
Oral histories (document genres) 4,836
Ordination sermons 3,599
Ouvrages pour la jeunesse 3,525
Online resources 2,456
Ouvrages illustrés 2,354
Orchestral music, Arranged 2,331
Orthographic drawings 2,020
Operettas 1,819
Ouvrages de référence 1,780
Ouvrages de vulgarisation 1,705
Ouvertures (Musique) 1,662
Online databases 1,578
Outline 1,425
Outdoor books 1,366
Outline maps 1,240
Ornate types (Type evidence) 1,161
Observers' manuals 1,132
Occult fiction 1,074
Outlines 1,058
One-act plays 1,005
Obituaries 811
Ouvrages de controverse 717
Original art 709
Officers' handbooks 701
Original cast recordings 630
Online-Publikation 593
Oral interpretation of poetry 560
Orchestral excerpts 543
Opera adaptations 504
Odes 502
Octavo format (Printing) 471
Offset lithographs 395
Oratory 373
Opera films 361
Old-time music 311
Opracowanie 289
Opera 281
Ouvrages apologétiques 281
Onitsha market literature 246
Official gazettes 243
One-page folding zines 236
One-sheet posters 216
Ornament drawings 204
Office du soir (Musique) 202
Oral history 186
Occasional poems 179
Onlays (Binding) 175
Optical disks 169
Offertories (Music) 154
Occasional sermons 153
Oil paintings (visual works) 153
Organ masses 153
Offprints 140
Operators' manuals 140
Ownership inscriptions 138
One-act operas 137
Orphans court records 136
Ouvrages de référence 130
Oil paintings 124
Occasional addresses 116
Ouvrages prélinnéens 116
Oregon authors 112
Ouvrages avant 1900 112
Open form music 111
Orations 106
Opéras de chambre 100
Organa 99
Orders in council 95
Original covers (Binding) 93
Obras ilustradas 92
Open access resources 87
Opera television programs 87
Outtakes 87
Occasional speeches 84
Obras anteriores a 1800 81
Osgoodiana 73
Online-Ressource 71
Oral histories (literary genre) 64
Ouvrages avant 1850 64
Octavo 59
Orphans Court records 58
Offertoires (Musique) 57
One-page folding-zines 55
Office du matin (Musique) 53
Open educational resources 52
Orchestral parts 51
Oriya fiction 51
Onlays 50