Reference sources (dictionaries, encyclopedias, thesauri, etc.) are useful when you are starting your research for background information on a subject or an issue. As you continue your research, they can be used to define new terms or concepts. Wikipedia, while not generally accepted as appropriate for citing in bibliographies, is very useful for general information and an overview of topics.
Do a keyword search with your topic in the A-Z List of Databases. Be careful not to make your search too specific: e.g. use "Anthropology", not "Australopithecus".
Cross-searchable Collections of Reference Titles