cover story vs work of fiction

cover story

noun
  • A fictitious account that is intended to hide one's real motive. 

  • A story included in a publication that is highlighted on the front cover. 

work of fiction

noun
  • A fictitious account; an account of events that never took place. 

  • A fictional account; a story. 

How often have the words cover story and work of fiction occurred in a corpus of books? (source: Google Ngram Viewer )