@article {tristan2009estimation, title = {Estimation of fiber orientation probability density functions in high angular resolution diffusion imaging}, journal = {NeuroImage}, volume = {47}, number = {2}, year = {2009}, pages = {638{\textendash}650}, publisher = {Elsevier}, author = {Antonio Trist{\'a}n-Vega and Carl-Fredik Westin and Santiago Aja-Fern{\'a}ndez} }