internally vs to oneself

internally

adv
  • Inwardly; spiritually. 

  • With regard to internal affairs. 

  • In an internal manner; within or inside of external limits; in an inner part or situation. 

to oneself

adj
  • Tending not to interact with others; introverted; reserved. 

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