Southworth, G. V. D., & Southworth, J. V. D. (1946). Early days in America: The period of exploration, the thirteen colonies, the intercolonial wars, the struggle for independence, the adoption of the Constitution, and our country's growifng frontiers. Iroquois Publishing Co..
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Southworth, Gertrude Van Duyn, و John Van Duyn Southworth. Early Days in America: The Period of Exploration, the Thirteen Colonies, the Intercolonial Wars, the Struggle for Independence, the Adoption of the Constitution, and Our Country's Growifng Frontiers. Syracuse, N.Y. : New York [etc.]: Iroquois Publishing Co., 1946.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Southworth, Gertrude Van Duyn, و John Van Duyn Southworth. Early Days in America: The Period of Exploration, the Thirteen Colonies, the Intercolonial Wars, the Struggle for Independence, the Adoption of the Constitution, and Our Country's Growifng Frontiers. Iroquois Publishing Co., 1946.