obdurate vs unmanageable

obdurate

adj
  • Stubbornly persistent, generally in wrongdoing; refusing to reform or repent. 

  • Hardened against feeling; hard-hearted. 

unmanageable

adj
  • Not manageable; not readily submitting to handling or management; not easily restrained, governed, or directed 

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