"Manual on Presentation of Data and Control Chart Analysis", MNL 7A, ISBN 0-8031-2093-1* Juran, Joseph M.; Godfrey, A. Blanton (1999).
"Manual on Presentation of Data and Control Chart Analysis", MNL 7A, ISBN 0-8031-2093-1* Juran, Joseph M.; Godfrey, A. Blanton (1999).