- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/spirit%C2%AEairlines%C2%AEcustomer%20service%E2%84%A2%20contact%20numbers%C2%AE%20%E2%80%93a%20step%20by%20step%20guide.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/SriLankan%C2%AE%20Airlines%C2%AE%20Helpline%20Numbers%20%E2%80%93%20direct%20access%20to%20customer%20care_0.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/Singapore%E2%84%A2Airlines%C2%AECustomer%20Service%E2%84%A2%20Contact%20Numbers%C2%AE%20%E2%80%93A%20Step%20by%20Step%20Guide.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/Southwest%E2%84%A2Airlines%C2%AECustomer%20Service%E2%84%A2%20Contact%20Numbers%C2%AE%20%E2%80%93A%20Step%20by%20Step%20Guide_0.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/Qatar%C2%AEAirways%C2%AECustomer%20Service%E2%84%A2%20Contact%20Numbers%C2%AE%20%E2%80%93A%20Step%20by%20Step%20Guide.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/Hawaiian%C2%AE%20Airlines%C2%AE%20Helpline%20Numbers%20%E2%80%93%20direct%20access%20to%20customer%20care_0.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/complete-qatar-airways-customer-service-24-7-live-person-support-numbers-step-by-step-human-guide.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/usa-qatar-airways-customer-service-phone-numbers-guide_2.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/complete-list-of-klm-airlines-customer-service-24x7-live-person-support-numbers-step-by-step-person_0.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/complete-list-klm-customer-service-247-live-support-numbers-guide_0.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/Delta%C2%AE%20Airlines%20USA%20Customer%20Service%20Contact%20Numbers%20_%20A%20Step-by-Step%20GUide%C2%AE_1.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/complete-list-united-airlines-customer-service-contact-numbers-usa-guide%20%281%29_0.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/Singapore%C2%AE%20Airlines%20USA%20Customer%20Service%C2%AE%20Contact%20Numbers_%20A%20Step-by-Step%20GUide%E2%84%A2%20.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/official-jetblue-phone-numbers-for-us-customers.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/qatar-airways-usa-customer-service-contact-numbers-step-by-step-guide.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/full-list-of-klm-airlines-customer-contact-service-numbers-usa-2025-guide%20%281%29.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/turkish-airlines-customer-service-numbers-24-7-live-support%20%281%29.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/expedia-us-customer-service-contact-numbers-step-by-step-guide%20%281%29_1.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/Singapore%C2%AE%20Airlines%20USA%20Customer%20Service%C2%AE%20Contact%20Numbers_%20A%20Step-by-Step%20GUide%E2%84%A2%20%20%281%29_3.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/Full%E2%84%A2-list-of-%7BAmerican%C2%AE%7D-airlines-customer-service-24-7-live-person-support-numbers-a-complete%E2%84%A2-GuiDe.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/expedia-us-customer-service-contact-numbers-step-by-step-guide%20%281%29%20%281%29.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/Copa%E2%84%A2%20Airlines%20Customer%20Service%E2%84%A2%20USA%20Contact%20Number%E2%84%A2_%20All-in-one%20guide%C2%AE.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/qatar-airways-usa-customer-service-contact-numbers-step-by-step-guide%20%281%29_0.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/complete-list-of-klm-airlines-customer-service-24x7-live-person-support-numbers-step-by-step-person%20%281%29.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/Alaska-usa-customer-service-contact-numbers-step-by-step-guide%20%281%29.pdf
- https://ppf.ucsf.edu/sites/ppf.ucsf.edu/files/webform/full-list-of-British-airline%C2%AE%EF%B8%8F-customer%C2%AE-servicetm-contact-numbers-in-the-usa-a-comprehensive-guid.pdf