Complex sentence: Further cooperation between German and Soviets took the form of an exchange of Polish POWs: following order by Lavrentiy Beria to the NKVD of October 3,1939, Polish prisoners detained in soviet camps were traded against POWs released by the Germans.
Split into simpler sentences: Further cooperation between German and Soviets took the form of an exchange of Polish prisoners of war. Following order by Lavrentiy Beria given to the NKVD on October 3,1939, Polish prisoners detained in Soviet camps were traded against POWs released by the Germans.