Rose-ringed parakeet Psittacula krameri populations and numbers in Europe: a complete overview - Schroeder, J; Parau; Stubbe, D; Mori; Menchetti; van, Kleunen; White, RL; Luna, A; Hernandez-Brito; Le, Louran; Clergeau, P; Albayrak; et al. (Open Ornithology Journal, 2016)