armistice vs cease-fire

armistice

noun
  • A (short) cessation of combat; a cease-fire, a truce. 

  • A formal agreement, especially between nations, to end combat. 

cease-fire

noun
  • In warfare, an agreed end to hostilities for a specific purpose. (Typically only temporary). 

How often have the words armistice and cease-fire occurred in a corpus of books? (source: Google Ngram Viewer )