https://support.google.com/edu/classroom/thread/335199557?hl=en&sjid=11445308492238211481-NA

https://forum.dimensionengineering.com/topic/21201-10-ways-to-reach-delta-airlines-customer-service-by-phone-chat-and-email-an-explained-guide/

https://support.google.com/admanager/thread/336466302?hl=en&sjid=4019853084657206234-NC

https://support.google.com/admanager/thread/336466251?hl=en&sjid=4019853084657206234-NC

https://www.goodreads.com/quotes/12702612-how-do-i-ask-a-question-at-expedia-to-ask

21 Ways to Call Air France Airlines Customer Service by Phone: A Complete Guide

https://support.google.com/admanager/thread/336465783?hl=en&sjid=4019853084657206234-NC

https://forum.dimensionengineering.com/topic/21138-ways-to-call-coinbase-customer-service-via-phone-number-chat-and-email-resolve-issues-quickly/

https://support.google.com/admanager/thread/336464865?hl=en&sjid=1946158818908309763-NC

https://forum.dimensionengineering.com/topic/21170-guide-to-contacting-united-airlines-customer-service-through-phone-email-chat-everything-you-need/