http://www.dgci.min-financas.pt/NR/rdonlyres/FDCA003F-EB88-475B-8E0F-21B1DFF7C43D/0/Circular_7-2007.pdf
http://www.dgci.min-financas.pt/NR/rdonlyres/D86A0F0A-B617-470A-B892-F41788BFEF02/0/Circular_8_2007.pdf
