Sesquiterpene Lactones from Centaurea Species: C. derventana and C. kosaninii - Tesšević, Vele; Vajs, Vlatka; Janaćković, Pedja; Todorovic, Nina; Djoković, Dejan; Marin, Petar; Milosavljevic, Slobodan (Planta Medica, 1998)