https://discuss.tindie.com/t/21-full-list-of-united-airlines-customer-care-contact-numbers-in-usa/524057
https://discuss.tindie.com/t/full-list-of-united-airlines-customer-service-usa-phone-numbers/524088
https://discuss.tindie.com/t/full-contact-information-for-united-airlines-support-in-the-usa/524143