Fonte:
http://info.portaldasfinancas.gov.pt/NR/rdonlyres/D0921D42-66D1-4152-A5A6-9543848187FA/0/Circular_1_2010.pdf
http://info.portaldasfinancas.gov.pt/NR/rdonlyres/9F8C2C61-1B4F-4647-93A5-053F2D5905C8/0/ficha_dout_2009_2731.pdf
http://info.portaldasfinancas.gov.pt/NR/rdonlyres/1E581491-A73D-44EE-9F2D-FDFC636B1B39/0/Inf_Vinc_art_71_CIRS_2010.pdf
http://info.portaldasfinancas.gov.pt/NR/rdonlyres/9E8481C0-7356-496C-AC4D-777F4EA783A4/0/Inf_vinc_CIRS_art_5_Proc_1866.pdf
http://info.portaldasfinancas.gov.pt/NR/rdonlyres/8D1549E6-9805-40B3-93E7-00860FA1ADB6/0/Artigo_21_ficha_doutrinaria.pdf
