https://regions-and-cities.europa.eu/sites/default/files/webform/multimedia_center/_sid_/How-to-Contact-Expedia-Customer-Service-via-phone-Guide.pdf
https://www.scienceforums.com/topic/92439-51-ways-to-contact-how-can-i-speak-to-someone-at-delta-airlinescare-a-full-usa-step-by/
https://www.scienceforums.com/topic/92739-6-ways-to-speak-and-talk-to-a-live-agent-at-alaska-airlines%C2%AE%EF%B8%8F-%E2%80%94-the-complete-guide/