An interview with the French ambassador about diplomacy in France would be considered a secondary source.
interview of Vietnam veteran
A television programme or a live interview would be an example of a non-written source.
A. primary source documents
An interview with a witness to a historical event would be the best example of a primary source, as it provides firsthand information from someone who experienced the event.
You would consult a primary source for a first and personal view of an historical event. Primary sources are original materials.
The readers guide to periodical literature
A suit would be best for an interview.
The most reliable source on topography in the United States is the U.S. Geological Survey.
It will be your fitness or gym trainer.
abc
to corroborate a given primary source's claim about an event