United States. Census Office. 6th census, 1840, & United States. National Archives and Records Service. (1967). 1840 census schedules of mines, agriculture, commerce, and manufacturing for Ohio. National Archives, National Archives and Records Service, General Services Administration.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)United States. Census Office. 6th census, 1840, و United States. National Archives and Records Service. 1840 Census Schedules of Mines, Agriculture, Commerce, and Manufacturing for Ohio. Washington: National Archives, National Archives and Records Service, General Services Administration, 1967.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)United States. Census Office. 6th census, 1840, و United States. National Archives and Records Service. 1840 Census Schedules of Mines, Agriculture, Commerce, and Manufacturing for Ohio. National Archives, National Archives and Records Service, General Services Administration, 1967.