2020-10-08T08:59:44.6100000Z
https://www.termdat.bk.admin.ch/entry/133881
BoBR Sprachenartikel, Ziff. 123.3 (BBl 1991 II 319)
FSO, The Party System in Switzerland, 2003, p. 28 ([Internet, 2020-10-07](https://www.bfs.admin.ch/bfsstatic/dam/assets/340176/master))
DFI, Quadrilinguisme en Suisse, 1989, p. 46
DFI, Quadrilinguismo svizzero, 1989, pag. 55