Gaya APA

(ETS), E, T, S. (2015). Official TOEFL iBT Tests Volume 1 / 托福考试官方真题集 1 (1st Edition). Beijing (北京市): 群言出版社.

Gaya MLA

(ETS), Educational, Testing, Service. "Official TOEFL iBT Tests Volume 1 / 托福考试官方真题集 1". 1st Edition Beijing (北京市): 群言出版社, 2015. Text.