Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:On the one hand, BC264 is devoid of anxiogenic effects (Derrien et al. 1994; Charrier et al. 1995), and exerts psychostimulant and memory-reinforcing properties (Ladurelle et al. 1997; Léna et al. 1999; Sebret et al. 1999); it
B. Bellier .
Category: