Fonte:
http://www.dgaiec.min-financas.pt/NR/rdonlyres/EE788933-B167-4761-B100-97090DFF7D40/0/Circular_n_25_2010_II.pdf
http://www.dgaiec.min-financas.pt/NR/rdonlyres/D5B5859D-DCF8-427C-8494-5CDD494835B5/0/Circular_n_26_2010_II.pdf
