"Referendums". ch.ch – A service of the Confederation, cantons and communes. Berne, Switzerland: Swiss Confederation. Diarsipkan dari asli tanggal 2017-01-10. Diakses tanggal 2017-01-09.
swissinfo.ch
Julia Slater (28 June 2013). "The Swiss vote more than any other country". Berne, Switzerland: swissinfo.ch – the international service of the Swiss Broadcasting Corporation. Diarsipkan dari asli tanggal 2017-07-13. Diakses tanggal 2015-07-27.
Duc-Quang Nguyen (17 June 2015). "How direct democracy has grown over the decades". Berne, Switzerland: swissinfo.ch – the international service of the Swiss Broadcasting Corporation. Diarsipkan dari asli tanggal 21 September 2015. Diakses tanggal 2015-07-27.
web.archive.org
"Referendums". ch.ch – A service of the Confederation, cantons and communes. Berne, Switzerland: Swiss Confederation. Diarsipkan dari asli tanggal 2017-01-10. Diakses tanggal 2017-01-09.
Julia Slater (28 June 2013). "The Swiss vote more than any other country". Berne, Switzerland: swissinfo.ch – the international service of the Swiss Broadcasting Corporation. Diarsipkan dari asli tanggal 2017-07-13. Diakses tanggal 2015-07-27.
Duc-Quang Nguyen (17 June 2015). "How direct democracy has grown over the decades". Berne, Switzerland: swissinfo.ch – the international service of the Swiss Broadcasting Corporation. Diarsipkan dari asli tanggal 21 September 2015. Diakses tanggal 2015-07-27.