New lignan, benzofuran and sesquiterpene derivatives from the roots of Leontopodium alpinum and L. leontopodioides - Dobner,M.J.; Ellmerer-Müller,E.P.; Schwaiger,S.; Batsugh,O.; Narantuya,S.; Stütz,M.; Stuppner,H. (Helv Chim Acta, 2003)