Wyss, B. (1990). Ragnarök of Illusion: Richard Wagner's Mystical Abyss at Bayreuth. October.
Citazione stile Chigago Style (17a edizione)Wyss, Beat. "Ragnarök of Illusion: Richard Wagner's Mystical Abyss at Bayreuth." October 1990.
Citatione MLA (8a ed.)Wyss, Beat. "Ragnarök of Illusion: Richard Wagner's Mystical Abyss at Bayreuth." October, 1990.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.