Sources : https://www.sciencedirect.com/science/article/pii/S2210539522001201#:~:text=Secondary%20airports%20have%20played%20a,exploit%20tourists%20lower%20time%20valuation. https://www.aviationpros.com/airports/airport-revenue/concessionaire-retail/article/21073287/the-rise-of-secondary-airports https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7445473/ https://www.sciencedirect.com/science/article/abs/pii/S2210539516300682 You can also add more sources if you find these are not enough, Use at least four sources, either directly or indirectly related to…