Fonte:
http://www.dgaiec.min-financas.pt/pt/destaques/stada_importacao/NEWS_stada_imp_21_10.htm
http://www.dgaiec.min-financas.pt/NR/rdonlyres/4499BE93-AAF2-4FC1-A1AA-8D7EF1435400/0/Circular_n_96_2008_II.pdf
