A historical dictionary may differ from a regular dictionary by holding more than definitions of words. It may include entries on important people, places, events, political parties, and institutions, as well as major political, economic, social, and cultural aspects. These entries can also be cross-referenced within the dictionary.
Other aspects of a historical dictionary include:
To discover dictionaries about an area, you can search by keyword or subject term of "dictionaries" e.g. Aboriginal Australians, History, Dictionaries, will find the Historical dictionary of Australian Aborigines.
Remember to keep your keywords or subject terms broad when you are searching for dictionaries or encyclopedias. Please note that not all dictionaries or sources that offer similar information will have these terms. History-specific keywords can be useful too such as "historiography".
Historical encyclopedias will usually have longer entries than historical dictionaries which may include expansive essays. They can range across all areas within a time period such as information on the archaeology and prehistory, the politics and culture, economics, institutions and organizations, wars and conflicts, and religions.
To discover encyclopedias about an area, you can search by keyword or subject term of "encyclopedias" and a geographical or subject area area e.g. "Australia" and "encyclopedia" will find, among other results, the Historical encyclopedia of Western Australia.