@article{ZhaoC03,
  title = {Understanding Symmetry in Object-Oriented Languages},
  author = {Liping Zhao and James Coplien},
  year = {2003},
  url = {http://www.jot.fm/issues/issue_2003_09/article3.pdf},
  tags = {meta-model, Meta-Environment, meta-objects},
  researchr = {https://researchr.org/publication/ZhaoC03},
  cites = {0},
  citedby = {0},
  journal = {Journal of Object Technology},
  volume = {2},
  number = {5},
  pages = {123-134},
}