Drawn into the PCdR group in Moscow , he worked under Ana Pauker .
In 1940 , Roller left for Bessarabia after the former province of Romania had been occupied by the Soviets .
Drawn into the PCdR group in Moscow , Roller worked under Ana Pauker .
In 1940 , Roller left for Bessarabia after the former province of Romania had been occupied by the Soviets .