centralization vs commixture

centralization

noun
  • The act or process of centralizing, or the state of being centralized; the act or process of combining or reducing several parts into a whole 

commixture

noun
  • The act or state of being mixed together; a union or mingling of constituents; commixtion. 

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