El-Sakkary, Ahmed K. On the existence of nominal plants. (English) Zbl 0686.93023 Int. J. Control 50, No. 5, 2093-2095 (1989). MSC: 93B35 93C05 PDFBibTeX XMLCite \textit{A. K. El-Sakkary}, Int. J. Control 50, No. 5, 2093--2095 (1989; Zbl 0686.93023) Full Text: DOI
El-Sakkary, Ahmed K. Estimating robustness on the Riemann sphere. (English) Zbl 0664.93022 Int. J. Control 49, No. 2, 561-567 (1989). MSC: 93B35 30E99 30C15 93D99 PDFBibTeX XMLCite \textit{A. K. El-Sakkary}, Int. J. Control 49, No. 2, 561--567 (1989; Zbl 0664.93022) Full Text: DOI