pretext vs subterfuge

pretext

noun
  • A false, contrived, or assumed purpose or reason; a pretense. 

verb
  • To employ a pretext, which involves using a false or contrived purpose for soliciting the gain of something else. 

subterfuge

noun
  • Deception; misrepresentation of the true nature of an activity. 

  • An indirect or deceptive device or stratagem; a blind. Refers especially to war and diplomatics. 

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