travelling salesman vs vendor

travelling salesman

noun
  • A man who travels, often within a certain territory, soliciting orders or selling goods. 

vendor

noun
  • A person or a company that vends or sells. 

  • A vending machine. 

verb
  • As the software vendor, to bundle one's own, possibly modified version of dependencies with a standard program. 

  • To bundle third-party dependencies with the source code for one's own program. 

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