https://forums.giantitp.com/showthread.php?684676-Contact-Methods-United-Airlines%AEUSA-Contact-Care-Numbers-An-All-inclusive-Guide&p=26260866#post26260866

https://forums.catholic-questions.org/threads/full-list-of-united-airlines%C2%AE-refund%E2%84%A2-service%C2%AE-usa-contact-number-a-complete-ultimate-guide.641490/

https://airlinesflight.zohodesk.com/portal/en/kb/articles/what-is-the-cheapest-day-to-fly-out-on-delta-29-8-2025

https://forums.catholic-questions.org/threads/full-list-of-expedi%F0%9D%93%AA%C2%AE-customer%E2%84%A2-service%C2%AE%EF%B8%8F-usa-contact-numbers-a-step-by-step-guide.641487/

https://forums.catholic-questions.org/threads/general-list-of-iberia%E2%84%A2%EF%B8%8F-contact%C2%AE%EF%B8%8F-numbers-in-the-usa%C2%AE%EF%B8%8F-24-7-liveperson-the-ultimate-detailed-guide.641481/

https://forums.giantitp.com/showthread.php?683929-Contact-Methods-United-Airlines%AEUSA-Contact-Care-Numbers-An-All-inclusive-Guide&p=26260086#post26260086

https://forums.catholic-questions.org/threads/full-list-of-lufthansa-airlines-customer%E2%84%A2-support%C2%AE%EF%B8%8F-usa-contact-numbers-your-expert-guide.641483/

https://forums.catholic-questions.org/threads/full-list-of-all-expedi%F0%9D%93%AA%C2%AE-customer%E2%84%A2-service%C2%AE%EF%B8%8F-usa-contact-numbers-full-guide.641479/

https://uqworld.org/t/ua-ota-official-delta-airlines-usa-contact-numbers-tm-an-official-guide/4966

https://forums.giantitp.com/showthread.php?684665-Complete-List-of-EasyJet-Customer%AE-Contact-Numbers-in-USA-A-Ultimate-step-by-step-Gu&p=26260853#post26260853