From first-hand sources, authenticated.

It's not as if we have no first-hand source of materials from outside of the solar system.

His work forms a crucial link to the artists of the 19th century, because he interested himself above all in first-hand sources.

This book contains many mentions of Schikaneder from first-hand sources.

Patrick Rambaud, a French author, wrote a fictionalized account of the conflict entitled "The Battle" using many first-hand sources.

Information from first-hand sources on Volga Bulgaria is rather sparse.

Research involves gathering new data from primary or first-hand sources or using existing data for a new purpose.

A first-hand source initially described them as members of the 14 Intelligence Company.

Ari's account of the events surrounding the conversion seems to be reliable; although he was born 67 years after the conversion, he cites first-hand sources.

However, he expressed concerns about the accuracy of the film, given the filmmakers' lack of first-hand sources about what actually happened in Munich.