I've read some threads quite before

so i already managed to add identifiers view from start also custom fields to view ids isolated, no problem thanks.
If amazon and google are stored in identifiers why those sudoc and worldcat should not be stored the same way? Sudoc provides localization and inter library loan, it's a basic need for students.
WorldsWithoutEnd, is it some kind of model extension for automating id type web link (Sudoc is not providing one neither other public libraries i may use)?
Thanks,
Gilles