1. Aradóttir, A. L. 1991. Population biology and stand development of birch (Betula pubescens Ehrh.) on disturbed sites in Iceland. Ph. D. thesis, Texas A & M University, Austin, TX.
2. Interactions between climate and terrestrial ecosystems;Atkinson;Trends Ecol. Evol.,1992
3. Holocene isochrone maps and patterns of tree-spreading inthe BritishIsles;Birks;J. Biogeogr.,1989
4. Vegetation on lava fields in the Hekla area, Iceland;Bjarnason;Acta Phytogeogr. Suec.,1991