Balinga, M., Sunderland, T., Walters, G., Issemb\'e, Y., Asaha, S.
and Fombod, E. (2006)
A vegetation assessment of the Waka national park, Gabon.
Herbier National du Gabon, LBG, MBG, WCS, FRP and
Simthsonian Institution, Libreville, Gabon. CARPE Report, 154 pp.
http://carpe.umd.edu/
Picard, N., Bar-Hen, A., Mortier, F. and Chadoeuf, J. (2009)
The multi-scale marked area-interaction point process: a model for
the spatial pattern of trees.
Scandinavian Journal of Statistics 36 23--41