Primo can be searched for eBook encyclopedia content.
Oxforld Bibliographies Online - collections of potential relevance: Art History; Atlantic History; British and Irish Literature; Literary and Critical Theory; Philosophy; Public Health; Sociology; Urban Studies; Victorian Literature
Oxford Reference Online - contains almost 200 dictionary, language reference, and subject reference works published by Oxford University Press
Encyclopedia of European social history from 1350 to 2000 (2001) print or eBook
The Atlantic World
Napoleonic Europe (1789-1815)
An encyclopaedia of Napoleon's Europe (1984) print
Eastern Europe
Encyclopedia of Eastern Europe: From the Congress of Vienna to the fall of communism (2000) print
Germany
Germany: A reference guide from the Renaissance to the present (2006) eBook
Modern Germany: An encyclopedia of history, people, and culture, 1871-1990 (1998) print
Britain
Twentieth-century Britain: An encyclopedia (1995) print
Poland
Kaleidoscope of Poland: A cultural encyclopedia (2015) print
Russia
Colonialism
Encyclopedia of Western colonialism since 1450 (2007) eBook
War
Twentieth-century war and conflict : a concise encyclopedia (2015) print
World War, 1914-1918 -- Encyclopedias.
Jewish History & Antisemitism
Encyclopedia of Jewish history and culture online (2017) eBook
Antisemitism: A historical encyclopedia of prejudice and persecution (2005) print
1919-1939
Encyclopedia of the interwar years : from 1919 to 1939 (2000) print
Subheadings "politics and government," "economic conditions," "social life and customs," "social conditions," and "intellectual life" can be useful in providing context for your topic.
When you have identified several primary subject headings on your topic, also search for "historiography" as a subject heading.
European history as a whole is demarked by the following dates: 1789-1900, but narrower subdivisions exist for nation-state and thematic histories. like "19th century," or "1848-1870."
When you are searching for subject headings as part of your quest for secondary sources, pay attention to subheadings like "Sources," "Maps," "Biography," "Correspondence," "Newspapers," "Personal Narratives," etc. The first of these indicates a collection of primary source types; the latter indicate specific types of primary sources.