Secondary sources are materials which provide an interpretation, analysis or discussion of information originally presented elsewhere. This is in contrast to primary materials which provide first-hand evidence. What counts as a secondary source depends heavily on the topic you are writing about and the discipline you are working within.
Scholarly articles are a common type of secondary source:
You can search for scholarly articles in two ways. First, via a general search over all library holdings. If performing a general search, it is important to use specific keywords to limit results to only those closely related to your topic (see tips below). Second, you can choose a subject-specific database and perform your keyword search there. When using a database, topics unrelated to the discipline of your interest have already been filtered out; you will receive fewer (but hopefully better!) results when searching.
If you are searching for a phrase, such as spontaneous combustion or greater rice weevil, put the entire phrase in double quotes. This will tell the search engine to only find results that contain the exact phrase, rather than one or two of the individual words.
If you have two or more words or concepts that you want to find, use AND (must be capitalized) to tell the search engine to only look for items that contain both words.
Often, there is more than one way to talk about your topic. For example, if you are looking at the study habits of college students, you could look for "study strategies," "study habits," "ways of studying," "study methods" etc. Some phrases might be better than others. If you want to try looking for multiple variations of the same word or phrase in a single search, use OR (all capitals) to tell the search engine to find material with any of the words you've included.
You can even get fancy and use both AND and OR:
Additionally, HeinOnline offers a complete U.S. Presidential Impeachment Library. Organized by the four affected presidents, this collection brings together a variety of documents both contemporaneous and asynchronous to each president's impeachment, presenting both a snapshot of the political climate as each impeachment played out and the long view history has taken of each proceeding. This collection offers background, primary, and secondary source material for your research.
The following three databases are commonly used by James Madison students. All three include full-text articles as well as citations to other articles that may be pertinent. If you can't find the full-text of an article, let me know & I'll help you figure it out!
Covers the history and culture of the US. It provides full-text coverage for 200+ journals and citations for articles in many more.
Includes academic humanities journals with full-text for many and citations for more. Several types of materials are included such as articles, interviews, bibliographies, and reviews.
Includes social sciences academic journals, includes full-text and citations.
**Tip** All three of the above databases use the same interface (i.e. they all look the same). At the top of the page, above the search box, you'll see "Searching: ..." with the name of the database. To the right, you can click on "choose databases" and then you can choose to search all three in one search.