Approximation based on orthogonal and almost orthogonal functions

@article{Antic2012ApproximationBO,
  title={Approximation based on orthogonal and almost orthogonal functions},
  author={Dragan Antic and Bratislav Dankovic and Sasa Nikolic and Marko Milojkovic and Zoran Jovanovic},
  journal={J. Franklin Institute},
  year={2012},
  volume={349},
  pages={323-336}
}