Https://mcmanuslab.ucsf.edu/sites/mcmanuslab.ucsf.edu/files/2025-07/2025-quick-guideline-10-ways-to-connect-to-united-airlines-u-s-a-customer-care.pdf https://mcmanuslab.ucsf.edu/sites/mcmanuslab.ucsf.edu/files/2025-07/2025-quick-guideline-10-ways-to-connect-to-united-airlines-u-s-a-customer-care.pdf