1. International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use, Impurities in New Drug Substances, ICH Harmonised Tripartite Guideline, February 2002, http://www.ifpma.org/ich1.html.
2. Exploratory chemometric analysis of the classification of pharmaceutical substances based on chromatographic data
3. R.E. Majors, LC-GC International March (2000) 232, http://www.chromatographyonline.com.
4. R.E. Majors, LC-GC International March (2001) 284, http://www.chromatographyonline.com.