https://www.devex.com/people/how-to-make-date-changes-to-your-United-booking-2271306
https://www.devex.com/people/understanding-United-s-flight-rescheduling-policy-2271321
https://www.devex.com/people/can-i-change-my-United-flight-for-free-2271335
https://www.devex.com/people/a-complete-guide-to-United-s-flight-change-procedures-2271352
https://www.devex.com/people/is-there-a-fee-for-changing-my-volaris-flight-date-2271840