pamphlet vs printed matter

pamphlet

noun
  • A small, brief printed work, consisting either of a folded sheet of paper, or several sheets bound together into a booklet with only a paper cover, formerly containing literary compositions, newsletters, and newspapers, but now chiefly informational matter. 

  • Such a work containing political material or discussing matters of controversy. 

verb
  • To distribute pamphlets (to someone or some place). 

  • To distribute pamphlets. 

printed matter

noun
  • Printed material produced by printers and publishers, including books, magazines, brochures, booklets, publicity material and newspapers, especially in relation to cheaper postage rates on such material. 

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