Reiko Heckel Alexey Cherchago Marc Lohmann A Formal Approach to Service Specification and Matching based on Graph Transformation. 37-49 2004 105 Electr. Notes Theor. Comput. Sci. http://dx.doi.org/10.1016/j.entcs.2004.05.006 db/journals/entcs/entcs105.html#HeckelCL04