https://www.yadvashem.org/yv/en/exhibitions/through-the-lens...
And also Vrba–Wetzler report
https://en.wikipedia.org/wiki/Vrba–Wetzler_report
I don't want someone to think that i'm blaming someone for reading stuff. I just think and see that sometimes for people it is very easy to forget or miss bad things (harm to society) when their salary (or income) depends on ignoring this.