[rsblue]

Down giùm mình bài này nữa. hi,
1) http://www.sciencedirect.com/science...6980950800104X

2) http://www.sciencedirect.com/science...52231009005524

3) http://ieeexplore.ieee.org/xpl/login...mber%3D6049600

then kiu vinamilk. :-*