Variation in the composition of the essential oil of commercial Valeriana officinalis L. roots from different countriesRaal, Ain; Arak, Elmar; Orav, Anne; Kailas, Tiiu; Müürisepp, Aleksander-MatiJournal of essential oil research2008 / 6, p. 524-529 https://www.researchgate.net/publication/241714499_Variation_in_the_Composition_of_the_Essential_Oil_of_Commercial_Valeriana_Officinalis_L_Roots_from_Different_Countries

Variation in the composition of the essential oil of Valeriana officinalis L. roots from EstoniaRaal, Ain; Orav, Anne; Arak, Elmar; Kailas, Tiiu; Müürisepp, Aleksander-MatiProceedings of the Estonian Academy of Sciences. Chemistry2007 / 2, p. 67-74