S
[Saw03] Zdeněk Sawa. Equivalence Checking of Non-flat Systems is EXPTIME-hard. In CONCUR'03, Lecture Notes in Computer Science 2761, pages 237-250. Springer-Verlag, August 2003. 
@inproceedings{concur2003-Saw,
  author =              {Sawa, Zden{\v{e}}k},
  title =               {Equivalence Checking of Non-flat Systems is
                         EXPTIME-hard},
  editor =              {Amadio, Roberto and Lugiez, Denis},
  booktitle =           {{P}roceedings of the 14th {I}nternational
                         {C}onference on {C}oncurrency {T}heory
                         ({CONCUR}'03)},
  acronym =             {{CONCUR}'03},
  publisher =           {Springer-Verlag},
  series =              {Lecture Notes in Computer Science},
  volume =              {2761},
  pages =               {237-250},
  year =                {2003},
  month =               aug,
}
List of authors