https://pantip.com/topic/43606698

https://intercom.help/agregar-infante/en/articles/11719512-como-hable-con-un-agente-en-vivo-en-qatar-airlines

https://nch.invisionzone.com/topic/87613-5-easy-ways-to-call-to-someone-at-delta-via-phone-email-or-chat-options-a-step-by-step-guide/

https://intercom.help/agregar-infante/en/articles/11719496-como-llamar-a-un-agente-en-vivo-en-lufthansa-airlines

https://mforum2.cari.com.my/forum.php?mod=viewthread&tid=5455172

https://nch.invisionzone.com/topic/87611-ways-to-speak-to-someone-at-delta-via-phone-email-or-chat-options-a-step-by-step-guide/

https://collaboratory.gse.upenn.edu/sites/default/files/webform/telefono-%C2%BFcomo-puedo-hablar-con-una-persona-en-expedia.pdf

https://collaboratory.gse.upenn.edu/sites/default/files/webform/what-time-does-southwest-customer-service-work.pdf

https://intercom.help/agregar-infante/en/articles/11719467-como-llamar-a-un-agente-en-vivo-en-turkish-airlines

https://collaboratory.gse.upenn.edu/sites/default/files/webform/how-much-does-aeromexico-charge-to-change-a-flight.pdf