amass vs get hold of

amass

verb
  • To collect into a mass or heap. 

  • to gather a great quantity of; to accumulate. 

  • To accumulate; to assemble. 

get hold of

verb
  • To obtain. 

  • To pick up or grab. 

  • To control or stabilize (oneself). 

  • To contact (a person). 

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