Pan Am: An Airline and Its Aircraft, by R.E.G. Davies (1987)
As with every book Ron Davies authored, this beautiful volume reflects his scholarly attention to detail, as well as his love of aviation. Complete with beautiful illustrations by Mike Machat, and Davies' outstanding maps, it’s an essential reference. (Hardcover)
https://www.amazon.com/Pan-Am-Airline-Its-Aircraft/dp/0517566397