brush up on vs peruse

brush up on

peruse

verb
  • To look over casually; to skim. 

  • To examine or consider with care. 

  • To read completely. 

  • To go from place to place; to wander. 

noun
  • An examination or perusal; an instance of perusing. 

How often have the words brush up on and peruse occurred in a corpus of books? (source: Google Ngram Viewer )