Fonte:
http://www.dgci.min-financas.pt/NR/rdonlyres/5D9CBF07-B8B6-4084-8975-472F8D815797/0/Circular_3-08-DSIRS.pdf
http://www.dgci.min-financas.pt/NR/rdonlyres/8A3A8274-DCD2-4524-A9AD-9FD9EA454388/0/Circular_4_%202008.pdf
