Yang Song Jian Fan Minrui Fei Taicheng Yang Robust H<sub> INFINITY </sub> control of discrete switched system with time delay. 159-169 2008 205 Applied Mathematics and Computation 1 http://dx.doi.org/10.1016/j.amc.2008.05.046 db/journals/amc/amc205.html#SongFFY08