Gaya APA
Rohr, R, &, E, A. (1990).
Discovering the Enneagram: An ancient tool for a new spiritual journey. Transl. by Peter Heinegg. : Das Enneagram: Die 9 Gesichter der Seele. 1989 .
New York:
New York Crossroad.
Gaya MLA
Rohr, Richard, &, Ebert,, Andreas.
"Discovering the Enneagram: An ancient tool for a new spiritual journey. Transl. by Peter Heinegg. : Das Enneagram: Die 9 Gesichter der Seele. 1989 ".
New York:
New York Crossroad,
1990.
Buku.