Helen Koral was the wike of Alexander Koral, both were Americans who worked for Soviet intelligence during World War II. The Koral's headed the "Art" or "Berg" group of Soviet spies. The Berg group acted as couriers for various Soviet contacts, including the Silvermaster ring. Helen Koral received a regular stipend of $100 per month from the KGB and work closely with Helen Lowry, the wife of Iskhak Akhmerov, the KGB Illegal Rezident during the World War II. Her code names in Soviet intelligence and as decipherered in the Venona materials is "Miranda", and later changed to "Art".
- 1251 KGB New York to Moscow, 2 September 1944
- 1524 KGB New York to Moscow, 27 October 1944
- 1582 KGB New York to Moscow, 12 November 1944
- 1636 KGB New York to Moscow, 21 November 1944, p. 1
- 1636 KGB New York to Moscow, 21 November 1944, p. 2
- 1636 KGB New York to Moscow, 21 November 1944, p. 3
- 1791 KGB New York to Moscow, 20 December 1944, p. 1
- 1791 KGB New York to Moscow, 20 December 1944, p. 2
- 1052 KGB New York to Moscow, 5 July 1945
- 337 KGB Moscow to New York, 8 April 1945.
- Allen Weinstein and Alexander Vassiliev, The Haunted Wood: Soviet Espionage in America—the Stalin Era (New York: Random House, 1999).
- Gorsky Memo: Translation of KGB file 43173 vol. 2 (v) pp. 46–55.
- John Earl Haynes and Harvey Klehr, Venona: Decoding Soviet Espionage in America, Yale University Press (1999), pgs. 152, 353.