 Complete the following phrase:  The Galician Soviet Socialist Republic , Г.С.С.Р. was a short-lived, self-declared Bolshevik political entity that existed from 15 July to formally 21 September 1920. The communist state was established during a successful counter-offensive of the Red Army in the summer of 1920 as part of the Polish-Soviet War and in the course of which the Polish-Ukrainian joint military force Polish Ukrainian Front was forced to retreat from its positions along the Dnieper that it 