• Letter of Bishop Josip Juraj Strossmayer to Mr. William E. Gladstone (Brief von Bishop Josip Juraj Strossmayer an Mr. William E. Gladstone). February 13, 1878 posted by Habsburg Web  
• The Three Emperors' League, Jan. 18th 1881 (Der Drei-Kaiser-Bund, 1881), from Avalon Project, Yale Univ. with reference to Bulgaria, Eastern Rumelia (mit Bezug auf Bulgarien, Ostrumelien)  
• Treaty of Berlin between Great Britain, Austria-Hungary, France, Germany, Italy, Russia and Turkey (Vertrag von Berlin zwischen Grossbritannien, Oesterreich-Ungarn, Frankreich, dem Deutschen Reich, Italien, Russland und dem Osmanischen Reich). July 13, 1878, excerpt, posted by ANN (the Armenian News Network)  
• The Treaty of Berlin, 1878, Excerpts on the Balkans, from Modern History Sourcebook
• The Greek Army and Bulgarian Peasants During the Second Balkan War (Die Griechische Armee und Bulgarische Bauern waehrend des Zweiten 
  Balkankrieges). Source: The Carnegie Endowment for International Peace, Report of the International Commission to Inquire into the Causes and Conduct of the Balkan Wars (Washington, DC: The Endowment, 1914). posted by Habsburg Web  
• The Bulgarian Declaration of Independence, 1908 (Bulgarische Unabhängigkeitserklaerung). Source: Anderson, Frank Maloy and Amos Shartle Hershey, Handbook for the Diplomatic History of Europe, Asia, and Africa 1870-1914. Prepared for the National Board for Historical Service. Government Printing Office, Washington, 1918. posted by V. Ferraro, Mt. Holyoke  
• Bernard Grant: The Flight of the Turks from Lule-Burgas, 1912 (Die Flucht der Türken von Lule-Burgas, 1912) from: Modern History Sourcebook  
• Tsar Nicholas' Declaration Against the Bulgarians (Zar Nikolaus' Erklärung gegen die Bulgaren) English translation from World War I Document Archive    

• Nordwestdeutsche Zeitung vom 18. Oktober 1912: Krieg auf dem Balkan
• The Formation of the Balkan Alliance of 1912 (Die Formierung der Balkan-Allianz von 1912). Source: Handbook 1918 (1)  
• The Efforts of the Powers to Prevent the Outbreak of the First Balkan War (Die Anstrengungen der Maechte, den Ausbruch des Ersten Balkankrieges zu verhindern). Source: Handbook 1918 (1)  
• Treaty of Peace between Greece, Bulgaria, Montenegro, Serbia on the one part and Turkey on the other part (Friedensvertrag zwischen Griechenland, Bulgarien, Montenegro, Serbien einerseits und der Türkei andererseits). London, May 17/30, 1913
• The Effort to Prevent Outbreak of the Second Balkan War, 1913 (Der Versuch, den Ausbruch des Zweiten Balkankrieges zu verhindern, 1913). Source: Handbook 1918 (1)
• The Treaty of London, 1913 (Der Londoner Vertrag, 1913) Source: Handbook 1918 (1)
• Treaty of Peace between Roumania, Greece, Montenegro, Serbia, and Bulgaria (Friedensvertrag zwischen Rumänien, Griechenland, Montenegro, Serbien und Bulgarien). Bucharest, July 28/August 10, 1913
• The Treaty of Bucharest, August 10, 1913 (Der Vertrag von Bukarest) Source: Handbook 1918 (1)
• The Treaty of Constantinople, 1913 (Der Vertrag von Konstantinopel (Istanbul)). Source: Handbook 1918 (1)

(1): Anderson, Frank Maloy and Amos Shartle Hershey, Handbook for the Diplomatic History of Europe, Asia, and Africa 1870-1914. Prepared for the National Board for Historical Service. Government Printing Office, Washington, 1918. posted by Mt. Holyoke

• "The Peace of Bucharest"--The Treaty of Peace between Roumania and the Central Powers. Signed At Bucharest ("Der Frieden von Bukarest", Friedensvertrag zwischen Rumänien und den Mittelmächten), 7 May, 1918, posted by V. Ferraro, Mt. Holyoke

• 1918: Report on War Guilt by the 'Commission on the Responsibility of the Authors of the War' (Bericht der Kommission bezüglich der Verantwortlichkeit der Verursacher des Krieges, bezüglich der Kriegsschuld), from World War I Document Archive

• Paris Peace Conference, July 29 to October 15, 1946, Report by Secretary Byrnes, October 18, 1946 (Bericht von US Staatssekretaer Byrnes von der Pariser Friedenskonferenz 1946), from: from Avalon Project, Yale Univ.
• Treaty of Peace with Bulgaria (Friedensvertrag der Alliierten mit Bulgarien). Paris, 10 February 1947, from: Australian Treaty Series