APA
Zeller H. v., . (1975). Approach to spirituality. London: The Catholic Book Club.
Chicago
Zeller Hubert van, . 1975. Approach to spirituality. London: The Catholic Book Club.
Harvard
Zeller H. v., . (1975). Approach to spirituality. London: The Catholic Book Club.
MLA
Zeller Hubert van, . Approach to spirituality. London: The Catholic Book Club. 1975.
