found: Jeschke, L. Prometeo, 1997:t.p. (Prometeo : ... Luigi Nonos Hörtragödie) p. 7 (Luigi Nonos Prometeo)
found: Grove music online, December 6, 2021(Prometeo, tragedia dell'ascolto (M. Cacciari), 1981-4, Venice, 1984, rev. 1985)
found: Nono, Luigi. Prometeo, ℗2018:label (Prometeo) booklet (libretto compiled by Massimo Cacciari from Aeschylus, Walter Benjamin, Friedrich Hölderlin, and others; for vocal and instrumental soloists, mixed chorus, four instrumental groups and live electronics, 1981-1985)