Krecsák, László; Wahlgren, Richard (2008). "A survey of the Linnaean type material of Coluber berus, Coluber chersea and Coluber prester (Serpentes, Viperidae)". Journal of Natural History. 42 (35–36): 2343–2377. Bibcode:2008JNatH..42.2343K. doi:10.1080/00222930802126888. S2CID83947746.
"Giftschlangen: Tod durch Kreuzotterbiss?" [Venomous snakes: death from adder bite?]. Gemeinsames Giftinformationszentrum Erfurt (in German). 4 May 2004. Archived from the original on 21 July 2011. Retrieved 6 September 2021.
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Krecsák, László; Wahlgren, Richard (2008). "A survey of the Linnaean type material of Coluber berus, Coluber chersea and Coluber prester (Serpentes, Viperidae)". Journal of Natural History. 42 (35–36): 2343–2377. Bibcode:2008JNatH..42.2343K. doi:10.1080/00222930802126888. S2CID83947746.
Krecsák, László; Wahlgren, Richard (2008). "A survey of the Linnaean type material of Coluber berus, Coluber chersea and Coluber prester (Serpentes, Viperidae)". Journal of Natural History. 42 (35–36): 2343–2377. Bibcode:2008JNatH..42.2343K. doi:10.1080/00222930802126888. S2CID83947746.
"Giftschlangen: Tod durch Kreuzotterbiss?" [Venomous snakes: death from adder bite?]. Gemeinsames Giftinformationszentrum Erfurt (in German). 4 May 2004. Archived from the original on 21 July 2011. Retrieved 6 September 2021.
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Steward JW (1971). The Snakes of Europe. Cranbury, New Jersey: Associated University Press (Fairleigh Dickinson University Press). 238 pp. LCCCN 77-163307. ISBN0-8386-1023-4.
Mehrtens JM (1987). Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN0-8069-6460-X.