Wolfgang Eichhorn is professor at the Karlsruhe Institute of Technology (KIT, formerly University of Karlsruhe(TH)), Faculty of Economics. His fields of research are economics, mathematics, operations research, mathematical modelling in economics, particularly in practise and theory of production, growth, distribution of wealth, games, prices, and price indices. He also published papers in statistics, especially on measurement in economics, and in insurance, mainly on macroeconomic aspects of risk management. He was research counsel for the German Research Foundation, the German Federal Cartel Office, the Munich Reinsurance Company, and for several national and international Scientific Publishing Companies. His research inspired his teaching: more than forty years mostly at Karlsruhe, but also, among others, at the Universities of Berkeley (UC), Bonn, Fribourg, Lisboa (TU), Los Angeles (USC), Rio de Janeiro (UF), Vancouver (UBC), Vienna (WU), Waterloo (UofW), Würzburg. Winfried Gleißner is a member of the Faculty of Business Administration at the University of Applied Sciences in Landshut, where he is responsible for mathematics and information technology. He is specialized on computer and network security. His fields of research are mathematical modelling in economics, particularly in the theory of growth, measurement in economics, taxes, distribution of wealth, price indices. He developped a model for the spread of computer viruses, which was recognized in the medical world. This influenced his teaching experience: some twenty years, mostly in Landshut, but also at the Technical Universites of Karlsruhe and Munich, the University of Applied Sciences in Rosenheim. Further he is a forensic expert in computer and network security, among others in credit cards.