Mapping gaps in an old-growth, secondary-growth, and selectively-logged tropical rainforest using discrete return LIDARJung, J., Pekin, B. K., Pijanowski, B. C.IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2013, 6(6), 2453-2461DOI: 10.1109/JSTARS.2013.2253306PublisherPDF