For use in the scanner field for linking back to the E-rara website's sheet music collection. This site has digitized engraved music scores from several Swiss libraries.
- Variable 1 = library holding the original. Values are as follows:
- CH-BEsu = Universitätsbibliothek Bern
- CH-Bu = Universitätsbibliothek Basel
- CH-C = Kantonsbibliothek Graubünden
- CH-Zz = Zentralbibliothek Zürich
- Variable 2 = the number at the end of the persistent link that follows "e-rara-".