collaboration vs refusal

collaboration

noun
  • Treasonous cooperation. 

  • The act of collaborating. 

  • A production or creation made by collaborating. 

refusal

noun
  • The act of refusing. 

  • Depth or point at which well or borehole drilling cannot continue. 

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