Ukrainian Nationalists and the Holocaust
Book by John Paul Himka (2021) which documents the Ukrainian ultra-nationalists (OUN, UPA) role in the WW2 mass murder of Jewish Ukrainians.
A Slaughter of Jews in Ukraine
Book by John Paul Himka, original post here: https://www.tabletmag.com/sections/history/articles/slaughter-of-jews-in-ukraine-lviv-pogrom