Fox, A. D., Kobro, S., Lehikoinen, A., Lyngs, P. and Väisänen, R. A. (2009) “Northern Bullfinch Pyrrhula p. pyrrhula irruptive behaviour linked to rowanberry Sorbus aucuparia abundance”, Ornis Fennica, 86(2), pp. 51–60. Available at: https://ornisfennica.journal.fi/article/view/133721 (Accessed: 16May2024).