Xuan Ju.
Estimating Image Motion in Layers: The "Skin and Bones" Model.
Department of Computer Science, University of Toronto, 1998.
(pdf), (ps.gz).

Fernando De la Torre,
Robust subspace learning for computer vision,
La Salle School of Engineering. Universitat Ramon Llull, Barcelona, Spain. 2002

Hedvig Sidenbladh,
Probabilistic Tracking and Reconstruction of 3D Human Motion in Monocular Video Sequences. TRITA-NA-0114, ISBN 91-7283-169-3, Dept. of Numerical Analysis and Computer Science, KTH, Stockholm, Sweden 2001.
(pdf).

Benjamin H. Sigelman
Video-Based Tracking of 3D Human Motion Using Multiple Cameras
Brown Unviersity, Department of Computer Science, Technical Report CS-03-08, 2003.
(pdf)