Fonte:
http://info.portaldasfinancas.gov.pt/NR/rdonlyres/D73D80B2-FB58-4DAE-9459-5CF2F188B920/0/Circular%20D.pdf
http://info.portaldasfinancas.gov.pt/NR/rdonlyres/4E498CDB-3CD1-4E85-A0B3-5A27AA7BF9B4/0/Circular%20F.pdf