internecine vs strifeful

internecine

adj
  • Characterized by struggle within a group, usually applied to an ethnic or familial relationship. 

  • Mutually destructive; most often applied to warfare. 

strifeful

adj
  • Full of strife; quarrelsome, polemic, contentious. 

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