Grimm, Jacob (1883). "XVII. Wights and Elves". Teutonic Mythology. Vol. 2. Translated by James Steven Stallybrass. W. Swan Sonnenschein & Allen. pp. 439–517.
Kolberg, Oskar (1874). "Zmora". Lud: jego zwyczaje [The People. Their Customs, Way of Life, Language..]. Vol. 7. Warszawa: Drukarni Jaworskiego. pp. 69–71. (Okolice Krakowa: część III. Gusła, Czary Przesądy)
Kolberg, Oskar (1882). "Zmora". Lud: jego zwyczaje [The People. Their Customs, Way of Life, Language..]. Vol. 15. Warszawa: Drukarni Jaworskiego. pp. 69–71. (W. Kreis Poznańskie)
Kolberg, Oskar (1884). "Zmora". Lud: jego zwyczaje [The People. Their Customs, Way of Life, Language..]. Vol. 17. Warszawa: Drukarni Jaworskiego. pp. 99–100.
Ármann Jakobsson (2009), "The Fearless Vampire Killers: A Note about the Icelandic Draugr and Demonic Contamination in Grettis Saga", Folklore, 120 (3): 307–316, doi:10.1080/00155870903219771, S2CID162338244
Ármann Jakobsson (2009), "The Fearless Vampire Killers: A Note about the Icelandic Draugr and Demonic Contamination in Grettis Saga", Folklore, 120 (3): 307–316, doi:10.1080/00155870903219771, S2CID162338244