Constitutional Act on the Czechoslovak Federation

The Constitutional Act on the Czechoslovak Federation (Czech: Ústavní zákon o československé federaci, Slovak: Ústavný zákon o česko-slovenskej federácii) was a constitutional law in Czechoslovakia adopted on 27 October 1968 and in force from 1 January 1969 to 1 January 1993 that affected the communist state constitution of the state. It converted the previously unitary Czechoslovak state into a federation.

Source: Wikipedia — Constitutional Act on the Czechoslovak Federation (CC BY-SA 4.0)