https://www.devex.com/people/what-are-the-rules-for-cancelling-united-airlines-tickets-2356070
https://www.devex.com/people/can-you-cancel-your-United-airlines-flight-and-receive-a-refund-2355769
https://www.devex.com/people/steps-to-cancel-an-United-airlines-first-class-ticket-2355945
https://www.devex.com/people/united-airlines-cancellation-policy-what-you-need-to-know-2356111
https://www.devex.com/people/can-you-cancel-a-United-flight-free-of-charge-2355316