[2] https://www.youtube.com/watch?v=CDeujOxl3jc (they are talking about this in the video: [3] https://en.wikipedia.org/wiki/Bykivnia )

[4] https://en.wikipedia.org/wiki/Vinnytsia_massacre

As the policies of Ukrainisation were halted (1931) and replaced by massive Russification approximately four-fifths of the Ukrainian cultural elite, intellectuals, writers, artists and clergy, had been "eliminated", executed or imprisoned, in the following decade. The term was coined for this - Executed renaissance.

Many would argue that Holodomor (1932-33, 2-10 millions of Ukrainian speaking people died) was a part of Russification campaign.