Ana M. D. Moreira José Luiz Fiadeiro Luis Filipe Andrade Evolving Requirements through Coordination Contracts. 633-646 2003 conf/caise/2003 CAiSE http://link.springer.de/link/service/series/0558/bibs/2681/26810633.htm db/conf/caise/caise2003.html#MoreiraFA03