The library collection will often contain different editions of the same work.
Historic editions
> For these, check the RISM, the online catalogue, or the paper catalogue.
Facsimile editions (facsimile of manuscripts or older editions)
> Focus on searching the catalogue. There are a number of collections of facsimiles.
eg. New York Performer’s Facsimiles (B-Bc 89.580)
The URTEXT editions
Urtext means "original text" and guarantees that this edition conforms with the original source.
Critical editions
These are academic editions, accompanied with a critical text explaining the choices made by the editor.
Complete works of the great composers.
In the library collection there are numerous collections of "Complete Works" of great composers, such as :
Johann Sebastian Bach, New Edition of the Complete Works, Bärenreiter (B-Bc XY-II-092); Franz Liszt, Neue Ausgabe sämtlicher Werke, Bärenreiter-EMB (B-Bc XY-I-075); Wolfgang Amadeus Mozart, Neue Ausgabe sämtlicher Werke, Bärenreiter (B-Bc XY-II-093)...