centering vs centralization

centering

noun
  • The process of moving something to a centre, normally before some other process. 

  • A type of formwork which serves as a temporary structure during the construction of arches and bridges. 

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 

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