intractableness vs summons

intractableness

noun
  • The state of being intractable; intractability. 

summons

noun
  • A call to do something, especially to come. 

  • A notice summoning someone to appear in court, as a defendant, juror or witness. 

  • A demand for surrender. 

verb
  • To serve someone with a summons. 

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