S. N. Balakrishnan Jie Ding Frank L. Lewis Issues on Stability of ADP Feedback Controllers for Dynamical Systems. 913-917 2008 38 IEEE Transactions on Systems, Man, and Cybernetics, Part B 4 http://dx.doi.org/10.1109/TSMCB.2008.926599 db/journals/tsmc/tsmcb38.html#BalakrishnanDL08