carnet vs visa

carnet

noun
  • An admission pass. 

  • A ticket book, a collection of tickets in the form of a booklet often sold at a discount to single tickets. 

  • A customs document that allows the temporary duty-free importation of a particular article 

visa

noun
  • A permit to enter and leave a country, normally issued by the authorities of the country to be visited. 

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