Helgesen, M., & Brown, S. (1994). Active listening: Building skills for understanding, student's book (1a. ed.). Cambridge University.
Citazione stile Chigago Style (17a edizione)Helgesen, Marc, e Steven Brown. Active Listening: Building Skills for Understanding, Student's Book. 1a. ed. Cambridge: Cambridge University, 1994.
Citatione MLA (9a ed.)Helgesen, Marc, e Steven Brown. Active Listening: Building Skills for Understanding, Student's Book. 1a. ed. Cambridge University, 1994.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.