Etris, S. F. (2011). The Pennsylvania Railroad Company test department, Altoona, PA: America's first industrial test laboratory (1874-1968). Wayne, PA: Philadelphia Chapter Pennsylvania Railroad Technical & Historical Society.
Chicago Style CitationEtris, Samuel F. The Pennsylvania Railroad Company Test Department, Altoona, PA: America's First Industrial Test Laboratory (1874-1968). Wayne, PA: Philadelphia Chapter Pennsylvania Railroad Technical & Historical Society, 2011.
MLA CitationEtris, Samuel F. The Pennsylvania Railroad Company Test Department, Altoona, PA: America's First Industrial Test Laboratory (1874-1968). Wayne, PA: Philadelphia Chapter Pennsylvania Railroad Technical & Historical Society, 2011.