Primary sources are original materials. They provide direct evidence or firsthand account of an event, experiment, person, company or object. Examples of primary sources include eyewitness accounts, interviews, autobiographies, drawings, statistical data, and journals articles reporting original research.
Secondary sources describe, summarize, review, interpret, and analyze primary sources. Examples of secondary sources include books and book chapters, newspapers, magazines, trade publications, and journals articles that describe and evaluate original research done by other people.
SEC filings, 10K reports
corporate policies and codes