References
- Bisgaard , S. , Quality and the Bottom Line , Qual Eng. , 7 ( 1 ), 223 – 235 ( 1994 ).
- Harry , M. and Schroeder , R. , Six Sigma , Doubleday , New York , 2000 .
- Drucker , P.F. , Management Task, Responsibilities and Practices , Harper & Row , New York , 1974 .
- Edited by George Box and Søren Bisgaard