APA

Rohr R., Ebert A. H. P. (., . (2001). The Enneagram. New York: Crossroad Publishing Co.

Chicago

Rohr Richard, Ebert Andreas Heinegg Peter (tr), . 2001. The Enneagram. New York: Crossroad Publishing Co.

Harvard

Rohr R., Ebert A. H. P. (., . (2001). The Enneagram. New York: Crossroad Publishing Co.

MLA

Rohr Richard, Ebert Andreas Heinegg Peter (tr), . The Enneagram. New York: Crossroad Publishing Co. 2001.