https://www.devex.com/people/da_guide-can-you-cancel-a-delta-flight-free-of-charge-2400779
https://www.devex.com/people/can-i-cancel-my-united-flight-without-penalty-2390874
https://www.devex.com/people/how-do-i-cancel-a-flight-and-get-a-refund-from-United-airlines-2319347
https://www.devex.com/people/change-of-heart-cancel-your-delta-airlines-flight-with-ease-2298406
https://www.devex.com/people/United-airlines-flight-cancellation-everything-you-need-to-know-2307523
https://www.devex.com/people/does-air-canada-offer-a-24-hour-flight-cancellation-policy-2277425