anon vs once more

anon

adv
  • At another time; then; again. 

  • Soon; in a little while. 

noun
  • An anonymous person, especially an author. 

  • A work with an unknown author. 

  • A work without a title. 

adj
  • anonymous 

once more

adv
  • Again, a further time, once again. 

  • Used other than figuratively or idiomatically: see once, more. 

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