credential vs memorialization

credential

noun
  • documentary or electronic evidence that a person has certain status or privileges 

verb
  • to furnish with credentials 

adj
  • Pertaining to or serving as an introduction or recommendation (to someone). 

memorialization

noun
  • The act or process of memorializing or creating a memorial. 

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