1. J. B. Harborne, Comparative Biochemistry of the Flavonoids, Academic Press, London, 1967
2. For earlier works see S. Hattori, Glycosides of Flavones and Flavonols, in The Chemistry of Flavanoid Compounds, /ed. T. Geissman/, p. 317, Pergamon Press, Oxford, 1962
3. G. Zemplen und R. Bognar, Ber. dtsch. chem. Ges. 74, 1818 (1941)
4. G. Zemplfen und R. Bognar, Ber. dtsch. ehem. Ges. 76, 773 (1943)
5. G. Zemplen und L. Farkas, Ber. dtsch. ehem. Ges. 76, 110 (1943)