@article {26, title = {The demography of range boundaries versus range cores in eastern US tree species}, journal = {Proceedings of the Royal Society B: Biological SciencesProceedings of the Royal Society B: Biological Sciences}, volume = {276}, number = {1661}, year = {2009}, pages = {1477-1484}, isbn = {0962-8452}, author = {Purves, Drew W} }