disciplinarian vs unyielding

disciplinarian

adj
  • Relating to discipline. 

noun
  • One who believes in discipline as a tool for regulation or control. 

  • One who exercises discipline. 

unyielding

adj
  • Not giving in; not bending; stubborn. 

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