Dale S. Caffall James B. Michael A New Paradigm for Requirements Specification and Analysis of System-of-Systems. 108-121 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2941&spage=108 2002 conf/rissef/2002 RISSEF db/conf/rissef/rissef2002.html#CaffallM02