Ivan Ivanov is a Professor of mathematics at the Faculty of Economics and Business Administration of the Sofia University “St. Kliment Ohridski”, Sofia, Bulgaria. He is the Head of the Statistics and Econometrics Department. Prof. Ivanov received his PhD (1994) and his Dr. Science degree (2007) from the same university. His research fields include the quantitative methods in economics, stochastic modeling and applications, game theory, matrix theory, nonlinear matrix equations and their applications. Ivan Ivanov has published over 100 papers, two monographs (in Bulgarian) and four textbooks (in Bulgarian). He serves on the editorial boards of two international mathematical journals.