Bensch S, Nilsson LGR, Nothagen P, Olsson P, Åkesson M. A Chiffchaff Phylloscopus c. collybita with mixed Chiffchaff and Willow Warbler Ph. trochilus song—genetic evidence. Ornis Svec [Internet]. 2001 Apr. 1 [cited 2024 Nov. 24];11(1–2):108-11. Available from: https://journals.lub.lu.se/os/article/view/22869