V. S. Rao, V. I. George, S. Kamath, and C. Shreesha, “Stability analysis of closed loop TRMS with observer based reliable H infinity controller using Kharitonov’s stability theorem”, IJET, vol. 7, no. 2.21, pp. 106–111, Apr. 2018, doi: 10.14419/ijet.v7i2.21.11846.