https://www.goodreads.com/topic/show/23049573-guide-faq-what-is-the-cheapest-day-to-buy-frontier-tickets
https://www.goodreads.com/topic/show/23049573-guide-faq-what-is-the-cheapest-day-to-buy-frontier-tickets
https://www.goodreads.com/topic/show/23049573-guide-faq-what-is-the-cheapest-day-to-buy-frontier-tickets