Svensson, T. A review of mass concentrations of Bramblings Fringilla montifringilla: implications for assessment of large numbers of birds. Ornis Svecica. 2021, 31: 44–67. arXiv:2010.08465. doi:10.34080/os.v31.22031.
Jenni, L. Mass concentrations of Bramblings Fringilla montifringilla in Europe 1900–1983: their dependence upon beech mast and the effect of snow-cover.. Ornis Scandinavica. 1987, 18 (2): 84–94. JSTOR 3676843. doi:10.2307/3676843.
Svensson, T. A review of mass concentrations of Bramblings Fringilla montifringilla: implications for assessment of large numbers of birds. Ornis Svecica. 2021, 31: 44–67. arXiv:2010.08465. doi:10.34080/os.v31.22031.
Jenni, L. Mass concentrations of Bramblings Fringilla montifringilla in Europe 1900–1983: their dependence upon beech mast and the effect of snow-cover.. Ornis Scandinavica. 1987, 18 (2): 84–94. JSTOR 3676843. doi:10.2307/3676843.