n.a space that is contained within another space

A sampling theorem for wavelet subspaces
Measures on the Closed Subspaces of a Hilbert Space
Acquiring linear subspaces for face recognition under variable lighting
Acquiring Linear Subspaces for Face Recognition under Variable Lighting
SUBSKY: Efficient Computation of Skylines in Subspaces
Experimental verification of decoherence-free subspaces.
Online identification and tracking of subspaces from highly incomplete information
Error and perturbation bounds for subspaces associated with certain eigenvalue problems
Catching the best views of skyline: a semantic approach based on decisive subspaces
Emergence of Phase- and Shift-Invariant Features by Decomposition of Natural Images into Independent Feature Subspaces