Structured Noncommutative Multidimensional Linear Systems. - Joseph A. Ball; Gilbert J. Groenewald; Tanit Malakorn (SIAM J. Control. Optim., 2005)

Bounded Real Lemma for Structured Noncommutative Multidimensional Linear Systems and Robust Control. - Joseph A. Ball; Gilbert J. Groenewald; Tanit Malakorn (Multidimens. Syst. Signal Process., 2006)

Equivalence of robust stabilization and robust performance via feedback. - Joseph A. Ball; Quanlei Fang; Gilbert J. Groenewald; Sanne ter Horst (Math. Control. Signals Syst., 2009)

Bounded real lemma and structured singular value versus diagonal scaling: the free noncommutative setting. - Joseph A. Ball; Gilbert J. Groenewald; Sanne ter Horst (Multidimens. Syst. Signal Process., 2016)