base form vs canonical form

base form

canonical form

noun
  • A standard or normal presentation of a mathematical entity or a text string, etc. 

  • Any of a set of representations of the resonance structure of a molecule each of which contributes to the real structure; a contributing structure. 

  • Synonym of dictionary form 

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