https://www.comicbookuniversebattles.com/index.php?/forums/topic/42989-lufthansa-airlines-customers-service-usa-contact-numbers-the-step-by-step-full-in-depth-guide/
https://www.comicbookuniversebattles.com/index.php?/forums/topic/42989-lufthansa-airlines%C2%AE%EF%B8%8F-customers%C2%AE%EF%B8%8F-service%C2%AE%EF%B8%8F-usa-contact-numbers-the-step-by-step-full-in-depth-guide/