The Soviet union republic imposed on occupied Latvia — proclaimed 21 July 1940 and incorporated into the USSR on 5 August 1940; unrecognized by most Western states.
Latvia restored its independence on 21 August 1991.
The atlas holds 2 border frames for Latvian Soviet Socialist Republic — the shape you scrub through changes in 1940 · 1944.
Verified single-volume history covering the Soviet annexation, German occupation and Soviet era. (Open Library verified: Kasekamp, 2010)
The standard account (with Rein Taagepera) of the Baltic states under Soviet rule. (Open Library verified: Misiunas, 1983/1992)