https://airlinesinfo.zohodesk.com/portal/en/kb/articles/c%C3%B3mo-llamar-a-delta-airlines-desde-per%C3%BA
https://official-united-helpline.bettermode.io/home/post/24-ways-to-call-united-airlines-customer-service-by-phone-number-and-g5riAz32cPk4rGS