Dietmar Ferger is a Professor at the Institute of Mathematical Stochastics, TU Dresden, Germany.Wenceslao González Manteiga is a Professor at the Department of Statistics and Operations Research, University of Santiago de Compostela, Spain.Thorsten Schmidt is a Professor at the Department of Mathematical Stochastics, University of Freiburg, Germany. Jane-Ling Wang is Distinguished Professor at the Department of Statistics, University of California, Davis, USA.