M. S. Moneeb, I. I. Hewala, H. A. Elmongy, and A.-A. M. Wahbi, “A New Concept for Testing Chromatographic Peak Purity: Application to Peak Purity Determination of Main Ingredients in Tea Extracts”, ajc, vol. 27, no. 10, pp. 3831–3837, Jun. 2015.