an Entity references as follows:
Petras Petrovičius Griškevičius (Russian: Пя́трас Пя́трович Гришкя́вичюс; 19 July 1924 in Rokiškis district – 14 November 1987 in Vilnius) was a Lithuanian communist party official in the Lithuanian SSR. He was the First Secretary of the Lithuanian Communist Party (de facto leader of Lithuania) from 1974 to his death.