Attributes / relations provided by
♦ ¹Orłowski, G., & Czarnecka, J. (2013). Re-evaluation of the role of the grey partridge Perdix perdix as a disperser of arable weed seeds. Journal of ornithology, 154(1), 139-144.
♦ ²del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.