by Derek Thompson, project director and editor, Charles E. Murphy, cartographer and editor, Joseph W. Wiedel, cartographer ; Frank W. Porter ... [and others]
a cooperative project of the three Commonwealth Research Universities ; Temple University, editors, David J. Cuff, William J. Young ; University of Pittsburgh, [editor], Edward K. Muller ; The Pennsylvania State University, [editors] Wilbur Zelinsky, Ronald F. Abler