A Pseudoconfiguration of Points without Adjoint. - Winfried Hochstättler; Stephan Kromberg (J. Comb. Theory, Ser. B, 1996)

The complexity of an inverse shortest paths problem. - Sándor P. Fekete; Winfried Hochstättler; Stephan Kromberg; Christoph Moll (Contemporary Trends in Discrete Mathematics, 1997)