Browse the Bibliography, Filmography and Webography
Old Bailey Online: The Proceedings of the Old Bailey - London's Central Criminal Court, 1674 to 1913. Sheffield, UK, 2003.
Old Maps Online. Portsmouth, UK, 2013.
Onderwijs: Digitale tentoonstellingen. The Netherlands.
Oorlogsbronnen (War Sources). The Hague.
Our Shared Legacy: World War II and "The Joint". New York, NY, 2015.
Oxford Research Encyclopedia of Asian History In Research Encyclopedia of Asian History. Oxford.
Paprik@2f (Portail Archives Politiques Recherches Indexation Komintern et Fonds français). Dijon, France, 2016.
Parallel History Project on Cooperative Security (PHP). Zürich, Switzerland.
Parnassus Scientiarum. Florence, Italy, 2000.
Peace and War in the 20th Century. Hamilton, Ontario, 2015.
Peacekeeping Fact Sheet., 2017.
Physicians for Human Rights (PHR): Library. New York.
Poland in Photographs, 1939-1944. New York.
Portugal 1914–1918. Portugal, 2014.
Poster Collection of the Hoover Institution. Hoover Institution, Libraries and Archives, Stanford, CA, 2015.
Powers of Persuasion: Poster Art from World War II. United States, 2015.
Primary Sources: Wars & Conflicts. Newport News, VA.
Princeton University Digital Library. Princeton.
Prisoners of the First World War: The ICRC Archives. Geneva, 2014.
Records of the Parliaments of Scotland. St Andrews, Scotland, UK, 2007.
Regesta Imperii. Mainz, Germany.