1. Szabolcs, I., The global problems of salt-affected soils, Acta Agron. Hung., 1987, vol. 36, pp. 159–172.
2. Chinese Pharmacopoeia Commission, Pharmacopoeia of People’s Republic of China, Beijing: China Medical Science Press, 2015.
3. Chen, M., Gan, L., Lin, S., Wang, X., Li, L., Li, Y., Zhu, C., Wang, Y., Jiang, B., Jiang, J., Yang, Y., and Shi, J., Alkaloids from the root of Isatis indigotica, J. Nat. Prod., 2012, vol. 75, pp. 1167–1176.
4. Wu, Y., Zhang, Z.X., Hu, H., Li, D., Qiu, G., Hu, X., and He, X., Novel indole C-glycosides from Isatis indigotica and their potential cytotoxic activity, Fitoterapia, 2011, vol. 82, pp. 288–292.
5. Wang, L.J., Jiang, W.B., Zhang, Z., Yao, Q.H., Matsui, H., and Ohara, H., Biosynthesis and physiological activities of 5-aminolevulinic acid (ALA) and its potential application in agriculture, Plant Physiol. Comm., 2003, vol. 39, pp. 185–192.