* "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.
* "Boris III of Bulgaria 1894—1943", Pashanko Dimitroff, London, 1986, ISBN 0-86332-140-2* "Crown of Thorns", Stephane Groueff, Lanham MD., and London, 1987, ISBN 0-8191-5778-3* "The Betrayal of Bulgaria", Gregory Lauder-Frost, Monarchist League Policy Paper, London, 1989.