Examples:

• an artifact, a document, a recording
• new scientific data, results, and theories
• official reports, speeches, pamphlets, posters, or letters by participants, and official election returns
• records created by organizations, such as registers of births, tax records, charters, other legal documents, etc.
• eyewitness accounts, oral interviews or documents created by a person with direct knowledge of a situation
• diaries, films, biographies, leading philosophical works, scientific works
• fictional sources such as novels or plays
• physical objects like photographs, newsreels, coins, paintings or buildings

Secondary sources:

• cite, comment on, or build upon primary sources

Note: a primary source may at times be treated like a secondary source