“…However, the same result, i.e., the confinement of all the roots in the aforementioned minor LHP sector (no roots in the corresponding major sector), had already been obtained well before by means of Routh-Hurwitz arguments (Usher, 1957;Luthi, 1942-43) or could easily have been achieved based on generalisations of the Routh-Hurwitz criteria (Hurwitz, 1895;Routh, 1877) to polynomials with complex coefficients (Frank, 1946;Billarz,1944). New formulations, extensions and improvements of similar algebraic conditions, including • the analysis of the critical cases and different tabular-form presentations, can be found in (Sivanandam & Sreekala, 2012;Chen & Tsai, 1993;Benidir & Picinbono, 1991;Agashe, 1985;Hwang & Tripathi; and, more recently, in (Bistritz, 2013) where numerically very efficient variants are presented . A different approach has been followed in (Kaminski et al, 2015) where, for q > 1, a test based on regular chains for semi-algebraic sets (Chen et al, 2013) has been suggested.…”