Three referendums were held in Switzerland in 1971.
[1] The first was held on 7 February on introducing women's suffrage at the federal level, and was approved by 66% of voters.
The second and third were held on 6 June on a constitutional amendment to introduce the human right to a non-hazardous environment and a federal resolution on federal finances.
In the first referendum in which women were allowed to vote, both were approved by voters.
[1]