Watkins, R. J. (1926). The construction industry in Ohio: A statistical analysis of a seasonal industry. Bureau of Business Research, Ohio State University.
Chicago-referens (17:e uppl.)Watkins, Ralph J. The Construction Industry in Ohio: A Statistical Analysis of a Seasonal Industry. [Columbus]: Bureau of Business Research, Ohio State University, 1926.
MLA-referens (8:e uppl.)Watkins, Ralph J. The Construction Industry in Ohio: A Statistical Analysis of a Seasonal Industry. Bureau of Business Research, Ohio State University, 1926.
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