Fonte:
http://www.dgci.min-financas.pt/NR/rdonlyres/5F1FA4F8-79F5-4104-AA5C-418F9DEB7375/0/Circular_13_2008.pdf
http://www.dgci.min-financas.pt/NR/rdonlyres/0BC4B8B8-6C24-46B1-B18C-6BA97FDD3E5E/0/Comunicado_MFAP_mod22.pdf
