This volume presents the proceedings of the 20th International Workshop on Graph-Theoretic Concepts in Computer Science (WG '94), held in Herrsching, Germany in June 1994.
The volume contains 32 thoroughly revised papers selected from 66 submissions and provides an up-to-date snapshot of the research performed in the field. The topics addressed are graph grammars, treewidth, special graph classes, algorithms on graphs, broadcasting and architecture, planar graphs and related problems, and special graph problems.

One ofthe most important aspects in research fields where mathematics is "applied is the construction of a formal model of a real system. As for structural relations, graphs have turned out to provide the most appropriate tool for setting up the mathematical model. This is certainly one of the reasons for the rapid expansion in graph theory during the last decades. Furthermore, in recent years it also became clear that the two disciplines of graph theory and computer science have very much in common, and that each one has been capable of assisting significantly in the development of the other. On one hand, graph theorists have found that many of their problems can be solved by the use of com puting techniques, and on the other hand, computer scientists have realized that many of their concepts, with which they have to deal, may be conveniently expressed in the lan guage of graph theory, and that standard results in graph theory are often very relevant to the solution of problems concerning them. As a consequence, a tremendous number of publications has appeared, dealing with graphtheoretical problems from a computational point of view or treating computational problems using graph theoretical concepts."

Graph-theoretic concepts are developed by computer scientists in order to model algorithms, nets, rewriting systems, distributed systems, parallelism, geometric and layout concepts. Their complexity is studied under various randomness assumptions. This volume contains contributions to the twelfth of a series of annual workshops designed to bring together researchers using graph-theoretic methods. Its purpose is to broadcast emerging new developments from and to a diversity of application fields. The topics covered include: Graph Grammars, Graph Manipulation, Nets, Complexity Issues, Algorithmic and Network Considerations, Outerplanar Graphs, Graph Isomorphism, Parallelism and Distributed Systems, Graphs and Geometry, Randomness Considerations, Applications in Chemistry, Specific Algorithms. N