@ARTICLE{Ling-AdapMeshApprMeth:11,
  author       = {Ling, L.},
  title        = {An Adaptive--Hybrid Meshfree Approximation Method},
  journal      = {Int. J. Numer. Methods Eng.},
  fjournal     = {International Journal for Numerical Methods in Engineering},
  volume       = {89},
  number       = {5},
  pages        = {637-657},
  year         = {2012},
  doi          = {10.1002/nme.3257}
}