notebook vs sheets

notebook

noun
  • A kind of user interface in literate programming, allowing calculations to be interspersed with human-readable comments, diagrams, etc. 

  • A book in which notes or memoranda are written. 

sheets

noun
  • Collective noun meaning a large amount, when used of rain, or other precipitation. 

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