1. (1) D. Ding and R. A. Cooper: “Electric powered wheelchairs”, IEEE Control Systems Magazine, Vol. 25, No. 2, pp. 22-34 (2005)
2. (2) R. A. Cooper, L. M. Widman, D. K. Jones, R. N. Robertson, and J. F. Ster: “Force sensing control for electric powered wheelchairs”, IEEE Trans. Control Syst. Technol., Vol. 8, No. 1, pp. 112-117 (2000)
3. (3) R. A. Cooper, D. K. Jones, S. Fitzgerald, M. L. Boninger, and S. J. Albright: “Analysis of position and isometric joysticks for powered wheelchair driving”, IEEE Trans. Biomed. Eng., Vol. 47, No. 7, pp. 902-910 (2000)
4. (4) R.-X. Chen, L.-G. Chen, and L. Chen: “System design consideration for digital wheelchair controller”, IEEE Trans. Ind. Electron., Vol. 47, No. 4, pp. 898-907 (2000)
5. (5) S. Katsura and K. Ohnishi: “Semiautonomous wheelchair based on quarry of environmental information”, IEEE Trans. Ind. Electron., Vol. 53, No. 4, pp. 1373-1382 (2006)