n.a legislative act is referred for final approval to a popular vote by the electorate

Referendums.
Referendums around the World
Appendix A: Referendums Around the World1
Referendums around the world : the growing use of direct democracy
Budget referendums and government spending: evidence from Swiss cantons
The Politics of Direct Democracy:Referendums in Global Perspective
Five Danish referendums on the European Community and European Union: A critical assessment of the Franklin thesis
Should PA associations take a stand on public policy initiatives and referendums?
Irish Voters Decide: Voting Behaviour in Elections and Referendums since 1918 by Richard Sinnott
Taking Cues on Europe? Voter competence and party endorsements in referendums on European integration