"The SS : Hitler's Instrument Of Terror / G. Williamson. - St. Paul, 1994. – p. 91" . "When Hitler invaded Poland in 1939-09, a special Einsatzgruppe was attached to each of the five German armies of the invasion force, with a sixth based in Posen. Einsatzgruppe IV was attached to the 4th Army. Each Einsatzgruppe was subdivided into Einsatzkommandos of 100 men.\n\nSS units, specially trained assassins, assigned terror tasks for the political administration in the Soviet Union and other eastern territories. The Einsatzgruppen worked behind the lines and murdered political opposition. The Einsatzgruppen murdered between 1.25-2 million Jews and tens of thousands of Soviet citizens and Soviet POWs."@eng . "Einsatzgruppe IV"@eng . .