Helgesen, M., & Brown, S. (1999). Active listening: Introducing skills for understanding : Level 1 [Đĩa CD-ROM]. Cambridge: Cambridge University Press.
Trích dẫn kiểu ChicagoHelgesen, Marc, và Steven Brown. Active Listening: Introducing Skills for Understanding : Level 1 [Đĩa CD-ROM]. Cambridge: Cambridge University Press, 1999.
MLA引文Helgesen, Marc, và Steven Brown. Active Listening: Introducing Skills for Understanding : Level 1 [Đĩa CD-ROM]. Cambridge: Cambridge University Press, 1999.
警告:這些引文格式不一定是100%准確.