duologue vs parley

duologue

noun
  • A dramatic performance or piece in the form of a dialogue limited to two speakers. 

  • A conversation between two persons; dialogue. 

parley

noun
  • A conference, especially one between enemies. 

verb
  • To have a discussion, especially one between enemies. 

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