https://ctl.gatech.edu/sites/default/files/webform/teaching_with_technology_partner/_sid_/how-to-speak-to-a-live-agent-at-united-airlines-call-support-now.pdf

https://ctl.gatech.edu/sites/default/files/webform/teaching_with_technology_partner/_sid_/talk-to-a-real-united-airlines-representative-today-full-guide.pdf

https://www.workingus.com/forums/topic/last-simple-ways-to-get-in-touch-with-united-airlines-customer-service-2/

https://www.workingus.com/forums/topic/13-ways-to-call-united-airlines%ef%b8%8f-usa-contact-numbers-a-full-detailed-guide/

https://ctl.gatech.edu/sites/default/files/webform/teaching_with_technology_partner/_sid_/15-ways-to-talk-to-someone-at-copa-airlines-via-phone-email-or-chat-options-a-step-by-step-guide.pdf