English Teaching Division. (1971). Carl Sandburg: His life, his poems, his land. United States Information Agency.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)English Teaching Division. Carl Sandburg: His Life, His Poems, His Land. Washington, D.C: United States Information Agency, 1971.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)English Teaching Division. Carl Sandburg: His Life, His Poems, His Land. United States Information Agency, 1971.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.