https://airlinescom.zohodesk.com/portal/en/kb/articles/1-877-827-8493-how-do-i-contact-lufthansa-customer-care
https://ctl.gatech.edu/sites/default/files/webform/teaching_with_technology_partner/_sid_/complete-guide-19-ways-to-speak-help-from-a-american-airlines-live-agent-customer-support_0.pdf
https://ctl.gatech.edu/sites/default/files/webform/teaching_with_technology_partner/_sid_/quick-ways-to-reach-expedia-customer-support-via-phone-chat-and-email.pdf
https://www.experts-exchange.com/questions/29290592/014-Simple-Ways-to-Reach-QuickBooks-Desktop-U-S-Support-A-Practical-Contact-Manual.html