•Primary: original information; eg. correspondence, diaries, research.
•Secondary: interprets primary information, eg. scholarly journals, books. This is where research is reported.
•Tertiary: interprets secondary information, eg. reference books, encyclopedias
Use for background information
•Reference sources: overview of topic eg. encyclopedias, in print or electronic.
•Books: analysis of topic, in depth background information.
•Journal articles: focus on specific subject.
•Grey literature: governments, organizations, think tanks – not publishers.
•Web pages: eg. government webpages such as gov.za.