Einfach, aber großartig : die Dampfloks der Reihe K4s der Pennsylvania Railroad
The railroad that never was : Vanderbilt, Morgan, and the South Pennsylvania Railroad
Railroads of Pennsylvania : your guide to Pennsylvania's historic trains and railway sites
In Council of Safety, Philadelphia, November 16th, 1776 : Sir, The fleet which sailed from New-York
Failure rates and data driven policies for vehicle safety inspections in Pennsylvania
The Ma & Pa : a history of the Maryland & Pennsylvania Railroad
Fueling the Gilded Age : railroads, miners, and disorder in Pennsylvania coal country
Grove City, Pennsylvania, ADAP Request No. 71-1-7-42-0035