https://ctl.gatech.edu/sites/default/files/webform/teaching_with_technology_partner/_sid_/Smooth-Ways-To-Call-How-Can-I-Talk-To-Someone-At-United-Airlines-Customer-Service-Full-Guide.pdf https://ctl.gatech.edu/sites/default/files/webform/teaching_with_technology_partner/_sid_/How-to-Contact-Frontier-Airlines-Customer-Service-via-phone-Guide.pdf https://ctl.gatech.edu/sites/default/files/webform/teaching_with_technology_partner/_sid_/seven-ways-to-call-expedia-customer-service-via-phone-email-or-chat-options-guide-step-by-step.pdf https://ctl.gatech.edu/sites/default/files/webform/teaching_with_technology_partner/_sid_/the-complete-guide-to-contacting-breeze-airways-phone-number-chat-email-options.pdf