https://www.devex.com/people/sa_info-how-late-can-i-cancel-my-singapore-airlines-flight-guide-2240899
https://www.devex.com/people/sa_info-how-late-can-i-cancel-my-singapore-airlines-flight-guide-2240899
https://www.devex.com/people/sa_info-how-late-can-i-cancel-my-singapore-airlines-flight-guide-2240899