Online resources 27,652 Outlines, syllabi, etc 5,794 Oral histories 3,618 Operas 3,534 Observations 2,317 Occult fiction 1,854 Outlines and syllabi 1,378 Ouvrages pour la jeunesse 1,336 Outlines 1,234 Overtures 1,118 Ordination sermons 1,074 Ouvrages illustrés 1,047 Ouvrages avant 1800 882 Outline maps 711 Observers' manuals 674 Oratorios 604 Online media 600 Orchestral excerpts 521 Occasional addresses 520 Occasional poems 500 Ouvrages de vulgarisation 459 Online-Publikation 374 Outdoor books 356 Offprints 328 Original cast recordings 320 Oregon authors 299 Online databases 265 Officers' handbooks 234 One-act plays 234 Obituaries 220 Orchestra studies 201 Occasional sermons 179 Orchestral music 172 Outline 112 Oral history 104 Opera 88 Opera films 79 Ouvrages de controverse 71 Obras ilustradas 65 Orders 62 Oratory 59 Online-Ressource 58 Oversize books 52 Occasional poetry 51 OverDrive ebook 51 Our world collection 50 Odes 46 Online book 43 Ouvrages de référence 42 Onlays 38 Occult fiction, American 36 Online video 36 OverDrive Audioebook 34 Obras anteriores a 1800 28 Opera adaptations 26 Old-time music 25 Opinion Papers 23 Ordinances 23 Obras populares 22 Offset lithographs 22 Onlays (Binding) 22 Opera television programs 21 Object category 20 Offertories (Music) 20 Olin Library Black authors 20 Ornate types (Type evidence) 20 Ouvrages avant 1850 20 Occasional verse 18 One-person shows (Performing arts) 18 Organ masses 18 Our Gang films 17 On-demand publications 16 Operators' manuals 16 Occasional speeches 15 On-demand printing 14 Ouvrages illustrés 14 Obras de divulgación 13 Open world video games 13 Oral interpretation of poetry 13 Other 13 Opera programs 12 Optical disks 12 Orchestral parts 12 Ouvrages apologétiques 12 Ouvrages avant 1900 12 Overland journals 12 Open form music 11 Orchestra accompaniment 11 Orchestral music, Arranged 11 Organ 11 Ownership inscriptions 11 Oboe 10 Obrazové publikace 10 Octavo format (Printing) 10 Official gazettes 10 Order-books 10 Ouvrages prélinnéens 10 Oil paintings 9 Ouvrages avant 1500 9 Oeuvrecatalogi (vorm) 8