coursebook vs reader

coursebook

noun
  • A textbook, a book designed to accompany a specific academic course, or one specified by the writers of the course to be read by its students. 

reader

noun
  • An elementary textbook for those learning to read, especially for foreign languages. 

  • A person who reads. 

  • A person who reads a publication. 

  • Any device that reads something. 

  • A literary anthology. 

  • A person who recites literary works, usually to an audience. 

  • A position attached to aristocracy, or to the wealthy, with the task of reading aloud, often in a foreign language. 

  • A person employed by a publisher to read works submitted for publication and determine their merits. 

  • Marked playing cards used by cheaters. 

  • A newspaper advertisement designed to look like a news article rather than a commercial solicitation. 

  • A university lecturer ranking below a professor. 

  • A book of exercises to accompany a textbook. 

  • A lay or minor cleric who reads lessons in a church service. 

  • Reading glasses. 

  • A proofreader. 

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