Nowlan, R. A. (2012). The American presidents, Washington to Tyler: What they did, what they said, what was said about them, with full source notes. McFarland & Co..
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Nowlan, Robert A. The American Presidents, Washington to Tyler: What They Did, What They Said, What Was Said About Them, with Full Source Notes. Jefferson, N.C.: McFarland & Co., 2012.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Nowlan, Robert A. The American Presidents, Washington to Tyler: What They Did, What They Said, What Was Said About Them, with Full Source Notes. McFarland & Co., 2012.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.