https://collaboratory.gse.upenn.edu/sites/default/files/webform/complete-list-of-spirit-airlines-customer-usa-direct-contact-numbers-live-all-in-guide.pdf
https://forums.giantitp.com/showthread.php?684960-Full-List-Of-Qantas-Airlines-%AE-Customer%AE-CUSTOMER-SERVICE-Numbers-In-The-Usa&p=26261212#post26261212
https://collaboratory.gse.upenn.edu/sites/default/files/webform/a-full-complete-list-of-quickbooks-desktop-support-number-usa-dial-in-numbers.pdf
http://forums.graphonomics.org/index.php?threads/quick-list%E2%84%A2-of-all-frontier%E2%84%A2-airlines-customer-support%C2%AE-usa-official-contact-numbers-a-complete-guide-2025.290716/