Gästebucheintrag von https://forms.business.columbia.edu/sites/forms/files-efs/webform/2023_deming_cup_nomination_and_a/_sid_/United%20Airlines%C2%AE%EF%B8%8FCustomer%E2%84%A2%20Support%20Number%202025%20%E2%80%93%20USA%20Toll-Free%20%26%20Help%20Lines.pd

https://forms.business.columbia.edu/sites/forms/files-efs/webform/2023_deming_cup_nomination_and_a/_sid_/United%20Airlines%C2%AE%EF%B8%8FCustomer%E2%84%A2%20Support%20Number%202025%20%E2%80%93%20USA%20Toll-Free%20%26%20Help%20Lines.pdf