Sussman, Linda Sue, The Speech of the Grail: An Initiation for Practitioners of Helping, Educational and Pastoral Professions Derived from 'Parzival' by Wolfram von Eschenbach. PhD thesis, The Union Institute, 1992 (DissAbstr B 53 (1992), 3143f.)

Mündlichkeit:

Psychologie:

Steiner, Rudolf (Anthroposophie):