(2000). Distribution of 8th- Grade Students According to Frequency of Math Exams. U.S. Department of Education.
芝加哥风格引文Distribution of 8th- Grade Students According to Frequency of Math Exams. U.S. Department of Education, 2000.
MLA引文Distribution of 8th- Grade Students According to Frequency of Math Exams. U.S. Department of Education, 2000.
警告：这些引文格式不一定是100％准确.