piece of doggerel vs sonnet

piece of doggerel

sonnet

noun
  • A fixed verse form of Italian origin consisting of fourteen lines that are typically five-foot iambics and rhyme according to one of a few prescribed schemes. 

verb
  • To compose sonnets. 

  • To celebrate in sonnets; to write a sonnet about. 

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