Trends in Science Performance of 9-, 13-, & 17-year olds. US Department of Education.
芝加哥风格引文Trends in Science Performance of 9-, 13-, & 17-year Olds. US Department of Education.
MLA引文Trends in Science Performance of 9-, 13-, & 17-year Olds. US Department of Education.
警告：这些引文格式不一定是100％准确.