@INPROCEEDINGS {14865,
author={N. Leonor and D. Ferreira and R. F. S. Caldeirinha and T.  Fernandes},
doi={10.1109/URSIGASS.2011.6050813 },
booktitle={URSI General Assembly},
title={A simple scattering model for tree trunks},
year={2011},
month={August},
volume={1},
pages={1-4} 
}