1. "Auk." 117, "Forty-second supplement to the American Ornithologists' Union Check-list of North American Birds." 847 (2000)
2. W. Attridge, "British Birds." 90, "Magpie catching House Martin." 191 (1997)
3. D. Baden, "Vogelwelt." 72, "Elstern auf Vogeljagd." 166 (1951)
4. TR. Birkhead, "The magpies; The ecology and behaviour of Black-billed and Yellow-billed Magpies." 270 (1991)
5. EJ. Boog, "British Birds." 59, "Magpie killing and eating Song Thrush." 309 (1966)