iron fist vs sticklerism

iron fist

noun
  • Ruthless and usually unrestricted control. 

  • Symbol of an army's tank or cavalry branch. 

sticklerism

noun
  • The behaviour of a stickler; inflexible adherence to rules. 

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