Geoffrey J.M. Parker, Julia A. Schnabel, Mark R. Symms, David J. Werring, and
Gareth J. Barker.
Nonlinear Smoothing for Reduction of Systematic and Random
Errors in Diffusion Tensor Imaging.
JOURNAL OF MAGNETIC RESONANCE IMAGING, 11:702-710, 2000.
(pdf)
(bibtex:
Parker-2000-NSR).