(1994). Speaking effectively.
Trích dẫn kiểu ChicagoSpeaking Effectively. 1994.
MLA引文Speaking Effectively. 1994.
警告：这些引文格式不一定是100％准确.
APA引文
(1994). Speaking effectively.
Trích dẫn kiểu ChicagoSpeaking Effectively. 1994.
MLA引文Speaking Effectively. 1994.