Complex sentence: The sisters Jarmila and Marie Šťulíks were selected for the'Aryanisation' programme (both were found and returned after the war); the remaining 11 were sent to the Chełmno extermination camp and in summer 1942 gassed (together with one girl from Lidice).
Split into simpler sentences: The sisters Jarmila and Marie Šťulíks were selected for the'Aryanisation' programme (both were found and returned after the war). The remaining 11 children were sent to the Chełmno extermination camp and in summer 1942 gassed (together with one girl from Lidice).