Callahan, A. (1992). Spiritual guides for today: Evelyn Underhill, Dorothy Day, Karl Rahner, Simone Weil, Thomas Merton, Henri Nouwen. Crossroad.
Chicago-referens (17:e uppl.)Callahan, Annice. Spiritual Guides for Today: Evelyn Underhill, Dorothy Day, Karl Rahner, Simone Weil, Thomas Merton, Henri Nouwen. New York: Crossroad, 1992.
MLA-referens (8:e uppl.)Callahan, Annice. Spiritual Guides for Today: Evelyn Underhill, Dorothy Day, Karl Rahner, Simone Weil, Thomas Merton, Henri Nouwen. Crossroad, 1992.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.