What is a primary source? They are the raw materials of historical research! Most often these are objects that were created during the time period being studied, and are the items and documents closest to the topic of investigation. Common types of primary sources include: diaries, music autographs, newspapers, government documents, and works of art. These should not be confused with secondary sources, which are interpretations of or commentary on primary sources. The most common secondary sources you will encounter are books and journal articles.