Https://help.boox.com/hc/en-us/community/posts/30850517820436--Cancel-Now-How-long-do-I-have-to-cancel-a-Delta-flight-without-penalty https://help.boox.com/hc/en-us/community/posts/30850517820436--Cancel-Now-How-long-do-I-have-to-cancel-a-Delta-flight-without-penalty https://help.boox.com/hc/en-us/community/posts/30850517820436--Cancel-Now-How-long-do-I-have-to-cancel-a-Delta-flight... https://help.boox.com/hc/en-us/community/posts/30850517820436--Cancel-Now-How-long-do-I-have-to-cancel-a-Delta-flight-without-penalty