There was a big Polish minority around Prnjavor in Bosnia. Locals called them Galcijani (because of Galicia). They “returned” to Poland (Bołeslawiec area) after WWII, in the fifties I think. There’s a book about that called “Galcijani i Srbi”, since they were called Serbs by the locals when they settled in Poland, because they came there from Serbian majority area. BTW Prnjavor area was sometimes called Small Europe, because there were some 27 different ethnic groups living there, including Poles (Galcijans), Czechs and Ukrainians.