P. Grünbacher, M. Halling, S. Biffl, H. Kitapci, B. Boehm:
"Repeatable quality assurance techniques for requirements negotiations";
in: "36th annual Hawaii international conference on system sciences", IEEE Computer Society Press, 2003, ISBN: 0-7695-1874-5, 23 - 31.
http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC04404378