https://www.smart-emotion.de/forum/thread/5276-full-list-of-united-airlines-u-s-phone-lines-for-reservations-baggage-support-20/
https://forum.gnoppix.org/t/full-list-of-ways-to-contact-united-airlines-in-the-u-s-2025-verified-phone-directory/1353
https://forum.gnoppix.org/t/full-list-of-united-airlines-u-s-phone-lines-for-reservations-baggage-support-2025/1354
https://www.smart-emotion.de/forum/thread/5277-full-list-of-u-s-based-united-airlines-contacts-for-fast-support-official-2025-o/
https://forum.gnoppix.org/t/full-list-of-u-s-based-united-airlines-contacts-for-fast-support-official-2025-overview/1356
https://www.smart-emotion.de/forum/thread/5278-21-full-list-of-united-airlines-customer-care-contact-numbers-in-usa/