Question: Four referendums were held in Switzerland during 1949, the first two were held on 22 May on revising article 39 of which third and current federal constitution of Switzerland?
Sentence (from "Swiss Federal Constitution"): The Federal Constitution of the Swiss Confederation (SR 10, German: "Bundesverfassung der Schweizerischen Eidgenossenschaft (BV)" , French: "Constitution fédérale de la Confédération suisse (Cst.)"
Relevant evidence: Yes