Essential oil content and composition in commercial Achillea millefolium L. herbs from different countriesRaal, Ain; Orav, Anne; Arak, ElmarJournal of essential oil bearing plants2012 / p. 22-31 https://www.academia.edu/56949794/Essential_Oil_Content_and_Composition_in_Commercial_Achillea_millefolium_L_Herbs_from_Different_Countries