Doff, A., & Becket, C. Listening 1 (4a ed.).
芝加哥风格引文Doff, Adrian, 与 Carolyn Becket. Listening 1. 4a ed.
MLA引文Doff, Adrian, 与 Carolyn Becket. Listening 1. 4a ed.
警告：这些引文格式不一定是100％准确.
APA引文
Doff, A., & Becket, C. Listening 1 (4a ed.).
芝加哥风格引文Doff, Adrian, 与 Carolyn Becket. Listening 1. 4a ed.
MLA引文Doff, Adrian, 与 Carolyn Becket. Listening 1. 4a ed.