English. Lawson, Jack (1997). Carl Nielsen. London: Phaidon Press. ISBN 0-7148-3507-2 Mogensen, Mogens Rafn (1992a) (ドイツ語). Carl Nielsen: Der dänische Tondichter:
https://books.google.com/books?id=kvA9AQAAMAAJ&pg=PA125&q=kraken Rafn, CarlChristian, ed (1829). “Kap. 21”. Ǫrvar-Odds saga. 2. Copenhagen: Enni Poppsku