Brown, S D; Dooling, R J (1993) Perception of conspecific faces by budgerigars (Melopsittacus undulatus): II. Synthetic models. J Comp Psychol 107:48-60 |
Brown, S D; Dooling, R J (1992) Perception of conspecific faces by budgerigars (Melopsittacus undulatus): I. Natural faces. J Comp Psychol 106:203-16 |