@article{Choon Ong2015, author = "Hong Choon Ong and Ekele Alih", title = "{A Control Chart Based on Cluster-Regression Adjustment for Retrospective Monitoring of Individual Characteristics - Fig 4}", year = "2015", month = "12", url = "https://plos.figshare.com/articles/figure/_A_Control_Chart_Based_on_Cluster_Regression_Adjustment_for_Retrospective_Monitoring_of_Individual_Characteristics_Fig_4_/1398749", doi = "10.1371/journal.pone.0125835.g004" }