https://ifutures.discourse.group/t/faqs-list-of-united-airlines-customer-service-contactnumbers-24-7livepersonassistance-guide/9899

https://www.bilibili.tv/en/video/4797508653553152

https://www.tracer900.net/topic/18040-complete-official-list-of-delta-airlines%C2%AE-customer%C2%AE%EF%B8%8F-service%E2%84%A2/

https://forums.thehuddle.com/topic/606400-complete-list-of-expedia%C2%AE%EF%B8%8F-customer-service%C2%AE-contact-numbers-in-usa-full-detaile...

https://ameblo.jp/travelhelpline/entry-12929657261.html

https://discourse.finalfurlong.org/t/complete-list-of-official-expedia-contact-numbers-in-the-usa-a-full-complete-2025-support-guide/12135

https://discourse.finalfurlong.org/t/full-list-of-expedia-customer-support-usa-contact-numbers-your-expert-guide/12106

https://www.buzzfeed.com/magicalghost172

https://www.console.playblackdesert.com/Community/Detail?topicNo=181204&topicType=6

https://www.forum-automatisme.net/viewtopic.php?t=8765