Watkins, R. J. (1926). The construction industry in Ohio: A statistical analysis of a seasonal industry. Bureau of Business Research, Ohio State University.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Watkins, Ralph J. The Construction Industry in Ohio: A Statistical Analysis of a Seasonal Industry. [Columbus]: Bureau of Business Research, Ohio State University, 1926.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Watkins, Ralph J. The Construction Industry in Ohio: A Statistical Analysis of a Seasonal Industry. Bureau of Business Research, Ohio State University, 1926.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.