1. Atlas of Seeds, Part 2: Cyperaceae;Berggren,1969
2. Atlas of Seeds, Part 3: Salicaceae-Cruciferae;Berggren,1981
3. Zadenatlas der Nederlandse Flora;Beijerinck;Biol. St. Meded.,1976
4. Quaternary Palaeoecology;Birks,1980
5. Pflanzensoziologie;Braun-Blanquet,1964