undocumented vs unsubstantiated

undocumented

adj
  • Lacking instructions or reference material. 

  • Not having official documentation required to legally enter, reside in, or work in a country. 

  • Not having official documents that provide identification, authorization, etc. 

noun
  • Synonym of undocumented immigrant 

unsubstantiated

adj
  • Lacking substantiation; without evidence. 

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