Hien Tran, T. et al. 2020. Extraction Process and Analysis of Components in Essential Oils of Piper longum Linn. Harvested in Dak Lak Province, Vietnam. Asian Journal of Chemistry. 32, 10 (Sep. 2020), 2639–2646. DOI:https://doi.org/10.14233/ajchem.2020.22564.