@article{3236,
  author       = {{Wehrheim, Heike}},
  journal      = {{Formal Methods in System Design}},
  number       = {{2}},
  pages        = {{143----170}},
  title        = {{{Behavioral Subtyping Relations for Active Objects}}},
  doi          = {{10.1023/A:1024764232069}},
  year         = {{2003}},
}