primary source

一次史料／ primary-source　—　Research

A record left by those present at the event or by their own age.

Greece — Ten drachmas, or two hundred ships? / The Strait of Salamis — Greece　Ten drachmas, or two hundred ships? ／ The Strait of Salamis

⚠ Just because it is a primary source does not mean it is correct. The person involved writes for their own convenience. Being primary only guarantees 'closeness', it does not guarantee 'correctness'.