https://www.pixiv.net/novel/show.php?id=24489096

https://flywithexpert.uvdesk.com/en/blog/delta-guide

https://hubpages.com/community/forum/366826/what-day-of-the-week-is-cheapest-to-book-delta-flights

https://support.google.com/admanager/thread/337099808?hl=en&sjid=3457116447235145825-NC

https://www.goodreads.com/quotes/12712557-faqs-does-expedia-actually-refund-money-when-you-need-assistance-with

https://travelsgroup.uvdesk.com/en/blog/your-guide-to-reaching-a-real-person-at-frontier-airlines

https://forum.dimensionengineering.com/topic/39226-ways-i-reach-out-to-the-american-airlines-customer-care-about-the-refund-policy/#comment-42769

https://www.goodreads.com/quotes/12710952-c-mo-hablar-con-un-representante-de-frontier-en-espa-ol

https://support.google.com/admanager/thread/337099808?hl=en&sjid=3457116447235145825-NC

https://hubpages.com/community/forum/366826/what-day-of-the-week-is-cheapest-to-book-delta-flights