James G. Nell Em delaHostria Richard L. Engwall Myong Kang Kurt Kosanke Juan Carlos Mendez Barreiro Weiming Shen System Requirements: Products, Processes and Models. 245-252 2002 conf/ifip5-12/2002 ICEIMT db/conf/ifip5-12/ifip5-12-2002.html#NelldEKKBS02