Helgesen, M., & Brown, S. (1994). Active listening: Building skills for understanding, student's book (1a. ed.). Cambridge University.
Cita Chicago (17th ed.)Helgesen, Marc, i Steven Brown. Active Listening: Building Skills for Understanding, Student's Book. 1a. ed. Cambridge: Cambridge University, 1994.
Cita MLA (9th ed.)Helgesen, Marc, i Steven Brown. Active Listening: Building Skills for Understanding, Student's Book. 1a. ed. Cambridge University, 1994.
Atenció: Aquestes cites poden no estar 100% correctes.