Stollen - The tunnel - YouTube

https://www.youtube.com/watch?v=KfSpNVipZTo&playnext_from=TL&videos=7Pfqm02atSw

Movie about Swiss underground aircraft tunels - caverns

Patrouille Suisse: Teamwork bei Tempo tausend

https://web.archive.org/web/20150117072642/http://www.air14.ch/internet/air14/de/tools/Info_medias/info_300814_1500.html

Jahresrapport der FU Br 41/SKS

https://web.archive.org/web/20150511012849/http://www.vtg.admin.ch/internet/vtg/de/home/verbaende/fub/fubr41/archiv/2014/jahresrapport_der.html

Jahresrapport der FU Br 41/SKS

https://web.archive.org/web/20150511012849/http://www.vtg.admin.ch/internet/vtg/de/home/verbaende/fub/fubr41/archiv/2014/jahresr