APA (7th ed.) Citation

Harnack. (1977). Group discussion: Theory and technique (2nd ed.). Prentice-Hall.

Chicago Style (17th ed.) Citation

Harnack. Group Discussion: Theory and Technique. 2nd ed. New Jersey: Prentice-Hall, 1977.

MLA (8th ed.) Citation

Harnack. Group Discussion: Theory and Technique. 2nd ed. Prentice-Hall, 1977.