Helgesen, M., & Brown, S. (1999). Active listening: Building skills for understanding : Level 2 [Đĩa CD-ROM]. Cambridge: Cambridge University Press.
استشهاد بنمط شيكاغوHelgesen, Marc, و Steven Brown. Active Listening: Building Skills for Understanding : Level 2 [Đĩa CD-ROM]. Cambridge: Cambridge University Press, 1999.
MLA استشهادHelgesen, Marc, و Steven Brown. Active Listening: Building Skills for Understanding : Level 2 [Đĩa CD-ROM]. Cambridge: Cambridge University Press, 1999.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.