Não informado. (1903). Circular of the Bureau of Standards. U.S. Department of Commerce, National Bureau of Standards.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Não informado. Circular of the Bureau of Standards. Washington: U.S. Department of Commerce, National Bureau of Standards, 1903.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Não informado. Circular of the Bureau of Standards. U.S. Department of Commerce, National Bureau of Standards, 1903.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.