The third and final book in the series by author Bob Withers showing and describing B&O motive power covers GP9 freight road switchers, the GP7 freight road switchers that didn't make it into Volume 2, GP7 and GP9 passenger road switchers, Baldwin freight road switchers, and higher horsepower EMD units. The book includes build dates and most locations, dates and dispositions.  Morning Sun 2018 New HB 128pp. NOS-BOP-WR3