Leslie Smith
Power and Mining Machinery Company, Milwaukee, Wis.
Siobhan Curham
Hartland Seymour
T. R Blackwood
Bart King
Carl Naske
Forschungsgesellschaft für das Strassenwesen (Austria). Arbeitsausschuss "Gebrochenes Steinmaterial."
Donald D. Carr
William T. W. Miller
Carl Mittag
Jerzy Nawrocki
Charles Peter Berkey
Lazarʹ Izrailevich Baron
B. V. Klushant͡sev
Gross, John J.
Ann Reit
Markus Olin
B. K. Baguant
Association of American Railroads. Railroad Committee for the Study of Transportation.