by Mine, M., Date, K., Ohmori, H., Sano, A., Todaka, Y., Nishida, H.
Published in IEEE International Conference on Control Applications, 1999 (20.01.2003)

by Logemann, H., Ryan, E. P.
Published in SIAM journal on control and optimization (2000)

by Goodwin, G., Johnson, C., Kwai Sin
Published in IEEE transactions on automatic control (01.12.1981)