Oxford shoe vs balmoral

Oxford shoe

noun
  • A type of leather shoe with lacing seamlessly integrated into the vamp, giving it a formal appearance. 

balmoral

noun
  • A Scottish cap with a flat top and a plume but no brim; a blue bonnet. 

  • A heavy walking shoe. 

  • A figured woollen petticoat. 

  • An Oxford shoe. 

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