AGG and GenGED: Graph Transformation-Based Specification and Analysis Rechniques for Visual Languages. - Roswitha Bardohl; Claudia Ermel; Ingo Weinhold (GraBaTs, 2002)

GenGED - A Visual Definition Tool for Visual Modeling Environments. - Roswitha Bardohl; Claudia Ermel; Ingo Weinhold (AGTIVE, 2003)