https://www.mmobugs.com/forums/index.php?threads/how-to-call-southwest-airlines-customer-service-full-step-by-step.36465/

https://www.emutalk.net/threads/united-airlines-customer-service-chat-and-email-support-how-to-reach-them.60651/

https://www.emutalk.net/threads/how-to-speak-to-a-united-airlines-customer-service-agent-quickly.60657/

https://www.perio.org/wp-content/uploads/ninja-forms/40/How-to-Contact-United-Airlines-Customer-Service-1-844-243-6776.pdf

https://www.perio.org/wp-content/uploads/ninja-forms/40/8-Ways-to-Reach-Southwest-Airlines-Customer-Service-by-Phone-Fast.pdf