Pennsylvania Railroad K-4 Project Reference
The Many Faces of the Pennsy K-4
Published by N.J. International
ISBN #0-934088-13-6
Pennsy K-4's Remembered
Frederick A. Kramer
©1992
Pennsylvania Railroad K-4s
Harry P. Albrecht
©1967
Pennsy Power
Alvin F. Staufer
©1962
Library of Congress No. 62-20878
Pennsy Power II
Alvin F. Staufer
©1968
Library of Congress No. 62-20872
Pennsy Power III
Alvin F. Staufer
©1993
ISBN #0-944513-10-7
