Prof. Stiebitz is professor of combinatorics/graph theory. His research area is structural and algorithmic graph theory, focusing on coloring problems for graphs. He lectures regularly to undergraduates in mathematics, engineering, and computer science. He mainly reads subjects such as combinatorics, game theory, and information and coding theory.
Graph Theory (click here for detailed information on this subject), in particular Graph Coloring Problems (click here for the book by T. Jensen & B. Toft)
Combinatorics, Cryptology and Linear Algebra