An improved HPLC-UV method for the simultaneous quantification of triterpenic glycosides and aglycones in leaves of Centella asiatica (L.) Urb (APIACEAE) - Rafamantanana, M H; Rozet, E; Raoelison, G E; Cheuk, K; Ratsimamanga, S U; Hubert, P; Quetin-Leclercq, J (J Chromatogr B Analyt Technol Biomed Life Sci, 2009)