Lougheed, L. (2021). Barron's IELTS (Fourth edition.). Kaplan, Inc., d/b/a Barron's Educational Series.
芝加哥风格引文Lougheed, Lin. Barron's IELTS. Fourth edition. New York, NY: Kaplan, Inc., d/b/a Barron's Educational Series, 2021.
MLA引文Lougheed, Lin. Barron's IELTS. Fourth edition. Kaplan, Inc., d/b/a Barron's Educational Series, 2021.
警告：这些引文格式不一定是100％准确.