Https://collaboratory.gse.upenn.edu/sites/default/files/webform/an-list-of-official-lufthansa-airlines-customer-service-contact-numbers.pdfhttps://collaboratory.gse.upenn.edu/sites/default/files/webform/an-list-of-official-lufthansa-airlines-customer-service-contact-numbers.pdf https://collaboratory.gse.upenn.edu/sites/default/files/webform/an-list-of-official-lufthansa-airlines-customer-service-contact-numbers.pdf