1. Bailey, I. W., 1956: Nodal anatomy in retrospect. J. Arnold Arb.37, 269?287.
2. Boodle, L. A., 1906: Lignification of phloem in Helianthus. Ann. Bot.20, 319?321.
3. Croizat, L., 1940: A comment on current notions concerning the leaf and bud scale of Angiosperms. Lingnan Science19, 49?66.
4. Eames, A. J., andL. H. McDaniels, 1951: Plant Anatomy. 2nd Ed., McGraw Hill Publ. Comp. Ltd., New York-London-Toronto 1951.
5. Engler, A., 1964: Syllabus der Pflanzenfamilien. 12. Aufl., 2. Band, Berlin 1964.