bellwether vs chapter and verse

bellwether

noun
  • Anything that indicates future trends. 

  • A stock or bond that is widely believed to be an indicator of the overall market's condition. 

  • The leading sheep of a flock, having a bell hung round its neck. 

chapter and verse

noun
  • Very full and detailed information. 

  • Specific references from an authoritative book or document, cited to support a statement or position. 

  • The chapter number and verse number (within a particular book) that locate a quotation from the Bible. 

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