| https://ehs.umich.edu/wp-content/uploads/formidable/48/guiacomo-hablo-con-una-persona-real-en-qatar-airways.pdf |
| https://ehs.umich.edu/wp-content/uploads/formidable/48/guia-como-llamar-a-qatar-airways-desde-mexico.pdf |
| https://ehs.umich.edu/wp-content/uploads/formidable/48/klm-guia-rapida-como-llamar-a-klm-airlines-desde-mexico.pdf |
