| 作者 | American Iron and Steel Institute, New York / Association of American Railroads. Bureau of Railway Economics. Library / Charles Osborn Mackey / D. H. Black / Fred Lavis / Institute of Radio Engineers. Technical committee on piezoelectric crystals / Institute of Radio Engineers. Technical committee on radio wave propagation / Jackson Square Levee Restoration Committee / M. Levy / Manitoba Power Commission / Philadelphia Electric Company / RCA Service Company / S. Mallein / United States Steel Corporation. Postwar Planning Committee / L. T. Wright |
