Https://mcmanuslab.ucsf.edu/sites/mcmanuslab.ucsf.edu/files/2025-07/american-airlines-customer-service-numbers-2025-full-guide-for-flight-changes-cancellations-booking-support-helpdesk.pdf https://mcmanuslab.ucsf.edu/sites/mcmanuslab.ucsf.edu/files/2025-07/american-airlines-customer-service-numbers-2025-full-guide-for-flight-changes-cancellations-booking-support-helpdesk.pdf