Reference
E. Gravano, E. Gravano, Filippo Bussotti, P. Grossoni, C. Tani (1999): Morpho-Anatomical and Functional Moddifications in Beech Leaves on the Top Ridge of the Apennines (Central Italy). – Phyton, Annales Rei Botanicae, Horn – 39_4: 41 - 46.