Marova, Irina, Vladimir Ivanitskii, Irina Ilina, Anastasya Pecheneva, Pavel Kvartalnov, Yury Belocon, and Maryana Belokon. “A New Contact Zone in the Chiffchaff Distribution Range: Caucasian and European Subspecies Meet Each Other in the South of Russia”. Ornis Fennica (March 22, 2024): 00–00. Accessed May 21, 2024. https://ornisfennica.journal.fi/article/view/131719.