Encyclopedias have an index that tells you which volume to look in for information on your topic. Textbooks have indexes that tell you what page in the book you'll find the information on. Most indexes are organized alphabetically by topic. These are special resources that refer you to periodical articles that contain information you need. Most periodical indexes today are computer databases.
Primary sources are the original resources that first report research or ideas.
These may include newspapers, research reports, scholarly journals, trade journals, conference proceedings, dissertations or Web sites. Secondary Sources Secondary sources are resources that analyze, describe, and synthesize the primary or original source. These include review articles, reference books such as encyclopedias and dictionaries, and textbooks. Take the Online Quiz Return to the top of the page.