History of Science, Technology, and Medicine (1975- ) is an index of books, book chapters, and journal articles. Some social sciences material is included. More information on this complex database.
PubMed (1947- ) is the National Library of Medicine's index to biomedical journal articles.
--To limit to historical sources, look for Article types at top of left-hand column. Open Customize. Deselect Clinical trial and Review; select Historical Articles. Hit Show at bottom. Then choose Historical Article.
--Be sure to look at the MeSH (Medical Subject Headings) at the bottom of pertinent records. You must have a record that says "Indexed for Medline" to do this.
Oxford Bibliographies Online are literature guides in several humanities and social sciences areas. They offer annotated lists of secondary source articles on particular subjects. Oxford Bibliographies by subject. Examples:
America: History and Life (1955- ) includes books, book chapters, journal articles, and book reviews.
Historical Abstracts (1954- ) includes books, book chapters, journal articles (but not book reviews) for non-North American history, 1450-date.
Note that in both America History and Life and in Historical Abstracts, you can limit your search to historical period covered (lower left of search screen).
JSTOR offers full-text of complete runs (up to about 5 years ago) of over 400 journals. Allows simultaneous or individual searching, full-text searching optional, of many African-American studies and historical journals. List of included journals.
Web of Science Citation Indexes allow citation searching, that is, starting with an article of interest and finding more recent articles that have cited it. More information.