https://ia902903.us.archive.org/15/items/delta-airlines-contact/full-list-of-delta-airlines-official-customer-service.pdf
https://ia902805.us.archive.org/32/items/airlines-delta-guide/Final_Verified_List_of_Delta_Airlines_CUSTOMER_SERVICE_Numbers_24_7.pdf
https://ia600502.us.archive.org/20/items/official-delta/FAQs_Final_list_Of_Delta_Official_Customer_Service.pdf
https://ia600505.us.archive.org/34/items/delta-airlines-customer/Official-List-Of-Delta-Airlines-Full-Customer-Service-Phone-Number.pdf
https://ia902901.us.archive.org/35/items/delta-quick-contact/Final_Verified_List_of_Delta_Airlines_CUSTOMER_SERVICE_Numbers_Contact_Live_Person.pdf