primary source

The most surprising thing right away was that, once you really look at the primary source material on multi-level marketing, which at the time was called pyramid selling, they really didn't hide how it worked.

These will then be stored on the seabed and recovered after the team has recovered the ship's hull, which investigators say is a primary source of evidence.

Mr Vaishnav said data from 2020 shows that online news was the primary source of information about India, followed by television, social media and word of mouth.

The proliferation of synthetic images makes the job of documentarians and researchers — safeguarding the integrity of primary source material, digging through archives, presenting history accurately — even more urgent.

China is the primary source of the precursor chemicals used to produce fentanyl.