Truong, D. M., Bich Thu, N. T. and Nghi, L. T. (2012) “Accumulation and variation of rosmarinic acid content in Orthosiphon stamineus Benth. based on phenological stages”, Academia Journal of Biology, 32(3), pp. 65–71. doi: 10.15625/0866-7160/v32n3.709.