1. Boominathan, I. S (2013). Analytical Techniques for the Determination of Heavy Metals in Herbal Drugs : A Review. Journal of Applied Pharmaceutical Science, (3)8,138-148.
2. Chan, K. M., et al. (2020). Application of Speciation Analysis in Herbal and Traditional Medicine. Current Trends and Future Perspectives : Trends in Analytical Chemistry, (126).
3. Kašpárková, J., et al. (2017). Speciation Analysis of Heavy Metals in Herbal Product. Food and Chemical Toxicology, (106), Pt. A,13-24.
4. Zhang, T., et al. (2018). Heavy Metal Speciation Analysis : A Review. Journal of Analytical Methods in Chemistry.
5. Zhang, Y., et al. (2015). Speciation Analysis of Arsenic, Chromium, and Mercury in Herbal Medicines. Journal of Analytical Methods in Chemistry.