EBSEES: 58 hits for Diplomatic History on page 6

The European Bibliography of Slavic and East European Studies (EBSEES) collects books, journal articles, reviews and dissertations from Eastern Europe (former countries of Eastern Bloc) which were published in Belgium, Germany, Finland, France, Great Britain, the Netherlands, Austria and Switzerland from 1991 to 2007. The segment "Literature" and "Culture" of the European Bibliography of Slavic and East European Studies contains 18.000 bibliographic entries (from the total asset of 85.000). More information can be found here.

Your search for Diplomatic History provides 58 hits
51	P. A. Tolstoy's dispatches as an original source of Ottoman history at the beginning of th 18th century Meyer, Michail, in: Acta Viennensia Ottomanica. Akten des 13. CIEPO-Symposiums (Comité International des Études Pré-Ottomanes et Ottomanes) vom 21. bis 25. September 1998 in Wien, 1999, p. 235-39
52	Vom Geachteten zum Geächteten. Erinnerungen des k. und k. Diplomaten und k. ungarischen Außenministers Emerich Csáky (1882-1961 Wien [etc.], Böhlau, 1992, 348 p
53	England and the North: the Russian Embassy of 1613-1614 [Pittsburg], PA, American Philosophical Society, 1994, xxxvi+236 p.
54	Ohne Protokoll : Amüsantes und Bitteres aus der Arbeit eines sowjetischen Diplomaten in Deutschland Bogomolov, Aleksandr Ja., Berlin, Ed. Ost, 2000, 167
55	The shaping of Russian foreign policy on Turkey and the Balkans, 1908-1911 [Zajcev] Zaitsev, V.V., in: Oxford Slavonic Papers, 32, 1999, p. 51-96
56	Die österreichisch-ungarische Politik gegenüber Sowjetrußland im Sommer und Herbst 1918. Die Mission des Generalkonsuls Georg de Pottere in Moskau Horčička, Václav, in: Österreichische Osthefte 46, 2004, pp. 485-514
57	A Russian advocate of peace : Vasilii Malinovskii (1765-1814) Ferretti, Paola, Dordrecht, London, Kluwer, 1998, xvii+248 p.
58	The Soviet Union: interventionism and the search for peace 1918-1934 Haigh, R.H.; Morris, D.S.; Peters, A.R., Sheffield, Hallam University, 1999, 197 p

The European Bibliography of Slavic and East European Studies (EBSEES) - 1991-2007