| https://curtiscenter.math.ucla.edu/wp-content/uploads/ninja-forms/76/1/frontier-airlines.pdf |
| https://curtiscenter.math.ucla.edu/wp-content/uploads/ninja-forms/76/1/agente-de-frontier.pdf |
| https://sdfdd.zohodesk.com/portal/en/kb/articles/today-frontier-787-c%C3%B3mo-puedo-comunicarme-con-frontier-airlines |
| https://www.goodreads.com/quotes/14451578-para-hablar-con-un-representante-de-frontier-en-espa-ol-puedes |
| https://sites.google.com/view/frontier-airline-pr/ |
| https://conference.csm.calpoly.edu/uploads/–Select_your_poster–.pdf |
