Tài liệu Kiril, Thân vương xứ Preslav

  • Bulgaria in the Second World War by Marshall Lee Miller, Stanford University Press, 1975.
  • Boris III of Bulgaria 1894–1943, by Pashanko Dimitroff, London, 1986, ISBN 0-86332-140-2
  • Crown of Thorns by Stephane Groueff, Lanham MD., and London, 1987, ISBN 0-8191-5778-3
  • The Betrayal of Bulgaria by Gregory Lauder-Frost, Monarchist League Policy Paper, London, 1989.
  • The Daily Telegraph, Obituary for "HM Queen Ioanna of the Bulgarians", London, 28 February 2000.