@article{zhuang_liu_anh_turner_2009, 
  title={Numerical Methods for the Variable-Order Fractional Advection-Diffusion Equation with a Nonlinear Source Term}, 
  volume={47}, 
  DOI={10.1137/080730597}, 
  publisher={Society for Industrial & Applied Mathematics (SIAM)}, 
  author={Zhuang and Liu and Anh and Turner}, 
  year={2009}
  }