https://serviceairlineshelpcarecom.zohodesk.com/portal/en/kb/articles/step-up-refund-is-air-france-good-with-refunds
https://serviceairlineshelpcarecom.zohodesk.com/portal/en/kb/articles/i-number-on-s-air-france-good-with-refunds
https://blog.ameba.jp/ucs/entry/srventryinsertend.do
https://www.deviantart.com/tumnoobho/art/1240776727?action=published