Operas 52,530
Orchestral music 16,144
Ouvrages illustrés 14,528
Outlines, syllabi, etc 14,029
Ouvrages avant 1800 11,705
Observations 10,923
Oral histories (literary works) 10,857
Oral histories 9,739
Organ music 8,565
Outlines and syllabi 8,400
Overtures 7,726
Oratorios 5,894
Oral histories (document genres) 4,836
Ordination sermons 3,600
Ouvrages pour la jeunesse 3,532
Online resources 2,456
Ouvrages illustrés 2,359
Orchestral music, Arranged 2,331
Orthographic drawings 2,020
Operettas 1,819
Ouvrages de référence 1,776
Ouvrages de vulgarisation 1,706
Ouvertures (Musique) 1,638
Online databases 1,579
Outline 1,425
Outdoor books 1,366
Outline maps 1,241
Ornate types (Type evidence) 1,161
Observers' manuals 1,131
Occult fiction 1,073
Outlines 1,058
One-act plays 1,005
Obituaries 812
Ouvrages de controverse 719
Original art 709
Officers' handbooks 700
Original cast recordings 629
Online-Publikation 593
Oral interpretation of poetry 560
Orchestral excerpts 543
Opera adaptations 504
Odes 502
Octavo format (Printing) 471
Offset lithographs 395
Oratory 374
Opera films 361
Old-time music 309
Opracowanie 289
Ouvrages apologétiques 282
Opera 281
Onitsha market literature 246
Official gazettes 244
One-page folding zines 237
One-sheet posters 216
Ornament drawings 204
Office du soir (Musique) 199
Oral history 186
Occasional poems 179
Onlays (Binding) 175
Optical disks 169
Occasional sermons 153
Offertories (Music) 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
Open form music 112
Oregon authors 112
Ouvrages avant 1900 112
Orations 106
Opéras de chambre 100
Organa 99
Orders in council 95
Original covers (Binding) 93
Obras ilustradas 91
Open access resources 87
Opera television programs 87
Outtakes 87
Occasional speeches 84
Obras anteriores a 1800 80
Osgoodiana 74
Online-Ressource 71
Oral histories (literary genre) 64
Ouvrages avant 1850 64
Octavo 59
Orphans Court records 58
Offertoires (Musique) 56
One-page folding-zines 55
Office du matin (Musique) 53
Open educational resources 52
Oriya fiction 52
Onlays 50
Orchestral parts 50