Real-Time Automated Concurrent Visual Tracking of Many Animals and Subsequent Behavioral Compilation. - John S. Zelek; David J. Bullock (ICCV, 2001)

Real-time tracking for visual interface applications in cluttered and occluding situations. - David J. Bullock; John S. Zelek (Image Vis. Comput., 2004)

Towards real-time 3-D monocular visual tracking of human limbs in unconstrained environments. - David J. Bullock; John S. Zelek (Real Time Imaging, 2005)