@InProceedings{improvingUML,
  author = 	 {Greg O'Keefe},
  year = 	 2006,
  title = 	 {Improving the Definition of {UML}},
  booktitle = 	 {Model Driven Engineering Languages and Systems},
  series =	 {Lecture Notes in Computer Science},
  number =       4199,
  pages =        {42-56},
  publisher =	 {Springer}
}