Fuente consultada Colegas en el bosque, D.L. 2007
Información encontrada DVD (directed by Roger Allers and Jill Culton ; written by Steve Moore ... [et al.] ; produced by Michelle Murdocca ; original music by Ramin Djawadi ; art direction by Luc Desmarchelier, Andrew Edward Harkness ; special effects by Chris Kazmier ; technical director (IMAX 3D release), Benjamin Aguillon)