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.
芝加哥风格引文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.
MLA引文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.
警告：这些引文格式不一定是100％准确.