Other samples of German soldiers' letters were sent home and copied during the war by a special Polish Home Army cell that infiltrated the German postal system. These letters have been analyzed by historians and the picture they paint is similar to views expressed by Levin and Uziel. Many soldiers wrote openly about the extermination of Jews and were proud of it. Support for ""untermensch"" and "master race" concepts were also part of the attitude expressed by German soldiers. Presented examples reflecting this trend include samples such as: