forged vs nonauthentic

forged

adj
  • Fake (as documents); falsified. 

  • Forged identification documents were used to enter the building. 

  • Fabricated by forging or at a forge, by working hot metal 

nonauthentic

adj
  • Not authentic. 

How often have the words forged and nonauthentic occurred in a corpus of books? (source: Google Ngram Viewer )