Fonte:
http://www.dgci.min-financas.pt/NR/rdonlyres/43CFAD1D-1DB7-4B73-BA23-B4E3EF8EE974/0/OficioCirculado_217702007.pdf
http://www.dgci.min-financas.pt/NR/rdonlyres/7656B029-2D57-4428-87BC-EEEEC90164BC/0/OficioCirculado_301022007.pdf
