glimpse vs look back

glimpse

verb
  • To see or view briefly or incompletely. 

  • To appear by glimpses. 

noun
  • A brief look, glance, or peek. 

  • A sudden flash. 

  • A faint idea; an inkling. 

look back

verb
  • Used other than figuratively or idiomatically: see look, back. 

  • To think of (past events) in retrospect. 

  • To reconsider or regret. 

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