https://www.mobilfunk-talk.de/thread/90652-complete-list-of-united-%F0%9D%93%90%F0%9D%93%B2%F0%9D%93%BB%F0%9D%93%B5%F0%9D%93%B2%F0%9D%93%B7%F0%9D%93%AE%F0%9D%93%BC-customer-contact-numbers-in-the-usa-the-ultimat/ https://forum.ls-chronicles.net/index.php?/topic/791-american-airlines%C2%AE%C2%AE-customer-service%E2%84%A2-usa-contact-numbers-a-step-by-step-full-guide/ https://forum.ls-chronicles.net/index.php?/topic/810-delta-airlines%C2%AE%C2%AE-customer-service%E2%84%A2-usa-contact-numbers-a-step-by-step-full-guide/