1. Vegetation and its environment in Denmark in the Early Weichselian Glacial (Last Glacial);Andersen;Geol. Surv. Denmark, Ser. 2,1961
2. An Introduction to Pollen Analysis;Erdtman,1943
3. Pollen Morphology and Plant Taxonomy. Angiosperms;Erdtman,1952
4. An Introduction to a Scandinavian Pollen Flora, I;Erdtman,1961