Töpfer, T. 2006.

The taxonomic status of the Italian Sparrow — Passer italiae (Vieillot 1817): Speciation by stabilised hybridisation? A critical analysis

. Zootaxa. 1325, 1 (Sep. 2006), 117–145. DOI:https://doi.org/10.11646/zootaxa.1325.1.8.