Ijaz Akhter Yaser Sheikh Sohaib Khan Takeo Kanade Nonrigid Structure from Motion in Trajectory Space. 41-48 2008 NIPS http://books.nips.cc/papers/files/nips21/NIPS2008_0607.pdf conf/nips/2008 db/conf/nips/nips2008.html#AkhterSKK08