Responsiveness to acoustic stimulation, distribution and habitat preferences of the Grey-headed Woodpecker, Picus canus, and the Three-toed Woodpecker, Picoides tridactylus, in Friuli-Venezia Giulia (North-eastern Italy). Rivista Italiana di Ornitologia, v. 84, n. 1, p. 41–52, 20 Mar.2015.