Harrison, L., Snelling, R., & Travis, P. (2021). Practice tests for IELTS (First edition.). HarperCollins.
芝加哥风格引文Harrison, Louis, Rhona Snelling, 与 Peter Travis. Practice Tests for IELTS. First edition. New York: HarperCollins, 2021.
MLA引文Harrison, Louis, et al. Practice Tests for IELTS. First edition. HarperCollins, 2021.
警告：这些引文格式不一定是100％准确.