%0 Journal Article %A Liu, Cheinshan %A Kuo, Chunglun %A Chang, Jiangren %D 2020 %J Computer Modeling in Engineering \& Sciences %@ 1526-1506 %V 122 %N 1 %P 33--48 %T Solving the Optimal Control Problems of Nonlinear Duffing Oscillators By Using an Iterative Shape Functions Method %M doi:10.32604/cmes.2020.08490 %U http://www.techscience.com/CMES/v122n1/38234