“History is always written by the winners. When two cultures clash, the loser is obliterated, and the winner writes the history books-books which glorify their own cause and disparage the conquered foe. As Napoleon once said, 'What is history, but a fable agreed upon?”
― Dan Brown, The Da Vinci Code
As Example, Do not read-only Right wing News Paper, Read both Right-wing and Left-wing newspapers. You can easily decide what is right and what is propaganda.