"Workers at US Steel's National Works, McKeesport, Pa., 1870 - 1960,"
http://www.library.pitt.edu/labor_legacy/SpecialTopicsII.html
Referenced in:
National Tube Works
"Workers at US Steel's National Works, McKeesport, Pa., 1870 - 1960,"
http://www.library.pitt.edu/labor_legacy/SpecialTopicsII.html
Referenced in:
National Tube Works