http://www.wilhelm-hansen.dk/en/_composer.asp?id=19 Arne Nordeim Biography, work list. http://www.schirmer.com/composers/nordheim/bio.html Arne Nordheim Biography. http://www.xs4all.nl/~gaud/biobak/n/nordheia.htm Arne Nordheim Biography, note on 'Tre Voci'.