Https://pressbooks.pub/travelservicemain/chapter/%f0%9d%9f%b7-%f0%9d%9f%be%f0%9d%9f%bb%f0%9d%9f%bb-%f0%9d%9f%bb%f0%9d%9f%bb%f0%9d%9f%b6-%f0%9d%9f%b6%f0%9d%9f%bf%f0%9d%9f%bd%f0%9d%9f%b7-what-is-the-basic-economy-on-united/ https://pressbooks.pub/travelservicemain/chapter/%f0%9d%9f%b7-%f0%9d%9f%be%f0%9d%9f%bb%f0%9d%9f%bb-%f0%9d%9f%bb%f0%9d%9f%bb%f0%9d%9f%b6-%f0%9d%9f%b6%f0%9d%9f%bf%f0%9d%9f%bd%f0%9d%9f%b7-what-is-the-basic-economy-on-united/