spring back vs take heart

spring back

verb
  • To recoil; to bounce back; to recover to an improved position. 

take heart

verb
  • To be courageous; to regain one's courage. 

intj
  • Used when encouraging someone to bear or take up a difficult situation. 

How often have the words spring back and take heart occurred in a corpus of books? (source: Google Ngram Viewer )