Fonte:
http://info.portaldasfinancas.gov.pt/NR/rdonlyres/E0205AF4-FFD1-4D0E-8EAA-96E7E47652CC/0/tratado%201557.pdf
http://info.portaldasfinancas.gov.pt/NR/rdonlyres/CD7ADA52-C088-4181-8520-21D5AE028889/0/tratado%201985.pdf
http://info.portaldasfinancas.gov.pt/NR/rdonlyres/AF22D62E-33EA-4DD6-A558-A7F76B657C83/0/tratado%201902.pdf