Lief Sjőberg (1984). "Symbolism in Denmark". In Anna Balakian (ed.). The Symbolist Movement in the Literature of European Languages. Comparative History of Literatures in European Languages. Amsterdam; Philadelphia, PA: John Benjamins. p. 589. doi:10.1075/chlel.ii. ISBN978-90-272-8642-0.
Lief Sjőberg (1984). "Symbolism in Denmark". In Anna Balakian (ed.). The Symbolist Movement in the Literature of European Languages. Comparative History of Literatures in European Languages. Amsterdam; Philadelphia, PA: John Benjamins. p. 589. doi:10.1075/chlel.ii. ISBN978-90-272-8642-0.