A sovereignty referendum was held in Tatarstan on 21 March 1992. Voters were asked whether they approved of Tatarstan being a sovereign state. The proposal was approved by 62% of voters.
Results
Do you agree that the republic of Tatarstan is a sovereign state, a subject of international law, building its relations with the Russian Federation and other republics (states) on an equal basis?
References
Tatarstani sovereignty referendum, 1992 Wikipedia(Text) CC BY-SA