https://support.google.com/edu/classroom/thread/328021011?hl=en&sjid=17669693420585063847-NA

https://superuser.com/questions/1883773/faaa-solve-what-does-flexible-cancellation-on-priceline-mean

https://www.goodreads.com/topic/show/23059958-is-air-france-open-on-24-7-open-policy-anytime

https://www.goodreads.com/topic/show/23059956-what-day-of-the-week-are-frontier-flights-cheapest-flight-hacks

https://support.google.com/googleplay/android-developer/thread/328020099?hl=en&sjid=11695214722672978547-NA

https://www.goodreads.com/topic/show/23059861-travel-faq-does-expedia-allow-free-cancellation

https://www.goodreads.com/topic/show/23059924-faqs-guide-does-expedia-allow-free-cancellation

https://support.google.com/edu/classroom/thread/328019972?hl=en&sjid=17429656526725193453-NC

https://superuser.com/questions/1883769/get-info-mean-what-does-refundable-mean-on-expedia

https://www.goodreads.com/topic/show/23059934-complete-guide-does-aeromexico-refund