1. Trees of North America and Europe;Phillips,1978
2. Flowers of Europe: A Field Guide;Polunin,1969
3. The Sibley Guide to Trees;Sibley,2009
4. Airborne and Allergenic Pollen of North America;Lewis,1983
5. Die Erreger des Heufiebers: Medizinisch-botanische Dokumentation der Pollenallergie in Mitteleuropa;Horak,1979