glimpse vs look into

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 into

verb
  • to investigate, explore, or consider 

  • Used other than figuratively or idiomatically: look into. 

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