Martín-Vivaldi, Manuel; Palomino, José J.; Soler, Manuel. Strophe length in spontaneous songs predicts male response to playback in the Hoopoe Upupa epops. Ethology. 2004, 110 (5): 351–362. doi:10.1111/j.1439-0310.2004.00971.x.
Hildebrandt, B.; Schaub, M. The effects of hatching asynchrony on growth and mortality patterns in Eurasian Hoopoe Upupa epops nestlings. Ibis. 2018, 160 (1): 145–157. doi:10.1111/ibi.12529.
Battisti, A; Bernardi, M.; Ghiraldo, C. Predation by the hoopoe (Upupa epops) on pupae of Thaumetopoea pityocampa and the likely influence on other natural enemies. Biocontrol. 2000, 45 (3): 311–323. S2CID 11447864. doi:10.1023/A:1009992321465.
Battisti, A; Bernardi, M.; Ghiraldo, C. Predation by the hoopoe (Upupa epops) on pupae of Thaumetopoea pityocampa and the likely influence on other natural enemies. Biocontrol. 2000, 45 (3): 311–323. S2CID 11447864. doi:10.1023/A:1009992321465.