Enlaces:
[1] https://www.edu.xunta.gal/centros/iescurtis/taxonomy/term/174
[2] https://www.edu.xunta.gal/centros/iescurtis/taxonomy/term/12
[3] http://www.xunta.es/dog/Dog2010.nsf/0e5fb445f3681a75c1257251004b10d7/2a2c75cea50446bdc12576d5006d8e30/$FILE/03900D005P012.PDF