@INPROCEEDINGS{AcetoEtAl10,
  author = 	 {Luca Aceto and Ignacio F\'abregas and de Frutos Escrig, David 
                  and Anna Ing\'olfsd\'ottir and Miguel Palomino},
  title = 	 {Relating modal refinements, covariant-contravariant 
                  simulations and partial bisimulations},
  booktitle =    {Fundamentals of Software Engineering,
                  4th IPM International Conference, FSEN 2011, 
                  Tehran, Iran, April 2011, Revised Selected Papers},
  editor = 	 {Farhad Arbab and Marjan Sirjani},
  series =       {Lecture Notes in Computer Science},
  publisher =    {Springer},
  volume =       7141,
  pages =        {268-283},
  year =         2011
}