https://support.google.com/edu/classroom/thread/326747107?hl=en&sjid=11921282876252340916-NA

https://gagadaily.com/backup2/index.php?/topic/6974-how-to-contact-delta-airlines-for-flight-booking-rescheduling-and-name-corrections/

https://support.google.com/edu/classroom/thread/326746265?hl=en&notify=new&sjid=6081229066158681666-NC

https://support.google.com/edu/classroom/thread/326745621?hl=en&sjid=11921282876252340916-NA

https://superuser.com/questions/1882251/faqs-solve-what-does-non-refundable-mean-on-expedia

https://superuser.com/questions/1882250/customer-helpus-is-expedia-non-refundable

https://philpeople.org/profiles/does-frontier-offer-fully-refundable-tickets-4

https://philpeople.org/profiles/does-frontier-offer-fully-refundable-tickets-5

https://philpeople.org/profiles/does-frontier-offer-fully-refundable-tickets-8

https://philpeople.org/profiles/does-frontier-offer-fully-refundable-tickets-6