http://www.biokids.umich.edu/guides/tracks_and_sign/tracks_key/tracks_mammal/
http://bdb.cma.gva.es/bdb2.jpg/
http://pasosdefauna.wordpress.com/2010/04/13/libros-sobre-huellas-y
http://www.secem.es/GALEMYS/PDF%20de%20Galemys/19%20%281%29/19.104._Lozano_35-8.pdf
http://www.sierradebaza.org/Fichas_fauna/fichas_fauna_general.htm#mamiferos
http://www.gpnc.org/tracks.htm
http://www.wildertrack.com/TripSight/ViewSpecies.aspx?SpeciesID=9421
http://www.biokids.umich.edu/guides/tracks_and_sign/
http://www.wildernesscollege.com/identify-deer-tracks.html
http://dirttime.ws/Who/WhoDoneIt.htm
http://www.cwf-fcf.org/en/resources/online-articles/news/wildlife/animal-tracks.html
http://www.barbastella.org/mastozoologia/rastros_mamiferos.htm
http://profesores.sanvalero.net/~w0548/FSVdocumentos/Huellas.pdf
http://www.proyungas.org.ar/publicaciones/pdf/Afiche%20Mamiferos%20para%20imprimir.pdf