armed struggle vs skirmish

armed struggle

noun
  • An irregular political conflict waged by an armed rebel group attempting to overthrow the prevailing regime or otherwise win political rights. 

skirmish

noun
  • A brief battle between small groups, usually part of a longer or larger battle or war. 

  • Any minor dispute. 

  • A type of outdoor military style game using paintball or similar weapons. 

verb
  • To engage in a minor battle or dispute 

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