United States. Library of Congress. (1990). Library of Congress classification schedules combined with additions and changes through 1989: Class D subclass DJK-DK History of Eastern Europe. (General), Soviet Union, Poland. Gale Research.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)United States. Library of Congress. Library of Congress Classification Schedules Combined with Additions and Changes Through 1989: Class D Subclass DJK-DK History of Eastern Europe. (General), Soviet Union, Poland. Detroit: Gale Research, 1990.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)United States. Library of Congress. Library of Congress Classification Schedules Combined with Additions and Changes Through 1989: Class D Subclass DJK-DK History of Eastern Europe. (General), Soviet Union, Poland. Gale Research, 1990.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.