Fonte:
http://info.portaldasfinancas.gov.pt/NR/rdonlyres/A5E0D1D3-7502-403F-B784-4FB8F8F5AFC8/0/inf1668.pdf
http://info.portaldasfinancas.gov.pt/NR/rdonlyres/9DC5CAE3-1507-4C3C-A2FE-DF68E9AC33D9/0/Inf%20%201405.pdf