Forward, William, The Play of the Planets in Eschenbach's Parzival, in Forward, William, Wolpert, Andrew, The Quest for the Grail, The Golden Blade, 47, Floris Books, Edinburgh, 1994, 85-98
in Forward und Wolpert 1994
Pädagogik:
Steiner, Rudolf (Anthroposophie):
, 782,14-782,30 (97)