The Prague Spring was a period of political liberalization in Czechoslovakia during the era of its domination by the Soviet Union after World War II. It began on January 5, 1968, when reformist Slovak Alexander Dubček came to power, and continued until August 21, when the Soviet Union and members of its Warsaw Pact allies invaded the country to halt the reforms. The Prague Spring reforms were an attempt by Dubček to grant additional rights to the citizens in an act of partial decentralization of the economy and democratization. The freedoms granted included a loosening of restrictions on the media, speech and travel. Dubček also federalized the country into two separate republics; this was the only change that survived the end of the Prague Spring. So, to answer your question specifically, the 1968 Prague Spring was ended when the Soviet Union and members of its Warsaw Pact allies invaded the country to halt the reforms.
Prague Spring contributed to the end of the USSR by the invasion of Czechoslovakia. The Prague Spring started in the year of 1968 and ended in the years of 1993.
The Prague Spring began on 5th of January, 1968 as the reformer Dubcek came to power, and was ended by a Soviet invasion on 21st of August, 1968.
Political Spring ended in 2000.
Spanish Guinea ended in 1968, when it became Equatorial Guinea.
Rites of Spring festival was created in 2004.
Spring Waltz ended on 2006-05-16.
Good Spring Railroad ended in 1871.
Terrytoons ended in 1968.
The Liverbirds ended in 1968.
Wojeck ended in 1968.
Høka ended in 1968.
The Contours ended in 1968.