Ritter, C., & Gilliard, J. (2007). ImpuR: A Collection of Diagnostic Tools Developed in R in the Context of Peak Impurity Detection in HPLC-DAD but Potentially Useful with Other Types of Time-Intensity Matrices. Journal of Statistical Software, 18(9), 1–18. https://doi.org/10.18637/jss.v018.i09