glancing vs perfunctory

glancing

adj
  • Making superficial, obtuse contact with something. 

noun
  • A sideways look; a glance. 

perfunctory

adj
  • Performed in a careless or indifferent manner as a thing of rote. 

  • Done only or merely to conform to a minimal standard or to fulfill a protocol or presumptive duty. 

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