On the request of Kheifetz and confirmed by [[Earl Browder]], Oppenheimer provided cooperation in access to research for several of KGB tested sources including a relative of Browder. <ref>''Special Tasks'', pg. 3.</ref><ref>Allen Weinstein and Alexander Vassiliev, ''The Haunted Wood: Soviet Espionage in America—the Stalin Era'', Random House, 1999. ISBN 0788164228 </ref> | On the request of Kheifetz and confirmed by [[Earl Browder]], Oppenheimer provided cooperation in access to research for several of KGB tested sources including a relative of Browder. <ref>''Special Tasks'', pg. 3.</ref><ref>Allen Weinstein and Alexander Vassiliev, ''The Haunted Wood: Soviet Espionage in America—the Stalin Era'', Random House, 1999. ISBN 0788164228 </ref> |