Osiejuk, T. S., Ratyńska, K., Dale, S., Steifetten, Øyvind, & Cygan, J. P. (2004). Ortolan Buntings Emberiza hortulana mimicking other species and other dialects of own species. Ornis Norvegica, 27, 73–79. https://doi.org/10.15845/on.v27i0.199