4Wu Chien -Wei,Pearn W L,Kotz Samuel. An overview of theory and practice on process capability indices for qualliy assurance[J]. International Journal of Production Economics, 2009,117(2) :338 -359.
5Linn Richard J, Tsung Fugee, Ellis Lau Wai Choi. Supplier selection based on process capability and price analysis [ J]. Quality Engineering, 2006, 18 (2) : 123 - 129.