@article{etna_vol20_pp154-163,
  author  = {Shipeng Mao and Shaochun Chen},
  title   = {Convergence analysis of the rotated $\mathcal{Q}_1$ element on anisotropic rectangular meshes},
  journal = {Electron. Trans. Numer. Anal.},
  volume  = {20},
  year    = {2005},
  pages   = {154--163},
}