National Archives and Records Administration II, RG 59, Records of the U. S. Department of State relating to internal affairs of Bulgaria 1910-1944, Washington, 1982 (Microfilm): Doc. 874.4016/ill. Original in English.
National Archives and Records Administration II, Records of the Department of State relating to internal affairs of Bulgaria 1910-1944, Washington 1982 (Microfilm-Edition): Doc. 874.4016/52, p. 1. Original in English.