Mattoccia, M., A. Romano, and V. Sbordoni. “Mitochondrial DNA Sequence Analysis of the Spectacled Salamander, Salamandrina Terdigitata (Urodela: Salamandridae), Supports the Existence of Two Distinct Species”. Zootaxa, vol. 995, no. 1, May 2005, pp. 1–19, doi:10.11646/zootaxa.995.1.1.