[1] Barták J.: Lyapunov Stability and Stability at Constantly Acting Disturbances of an Abstract Differential Equation of the Second Order. Czechoslovak Mathematical Journal, 26 (101) 1976, 411-437. MR 0415017

[2] Barták J.: The Lyapunov Stability of the Timoshenko Type Equation. Časopis pro pěstování matematiky, roč. 101, 1976, 130-139. MR 0445073

[3] Гантмахер Ф. Р.: Теория матриц. Издавательство Наука, Москва 1966. Zbl 1155.78304

[4] Leipholz H. H. E.: Stability of Elastic Rods via Liapunov's Second Method. Ingenieur - Archiv 44, 1975, 21-26. MR 0421234 | Zbl 0295.73041

[5] Nachlinger R. R., Faust C. D.: On the Stability of a Linearly Viscoelastic Bar. ZAMM 52, 1972, 179-181. MR 0307574 | Zbl 0255.73060

[6] Neustupa J.: The Uniform Exponential Stability and the Uniform Stability at Constantly Acting Disturbances of a Periodic Solution of a Wave Equation. Czechoslovak Mathematical Journal, 26 (101) 1976, 388-410. MR 0435565 | Zbl 0346.35012

[7] Parks P. C.: A Stability Criterion for a Panel Flutter Problem via the Second Method of Liapunov. Differential Equations and Dynamical Systems, 1967, 287-298.

[8] Wang P. K. C.: Stability Analysis of Elastic and Aeroelastic Systems via Lyapunovs Direct Method. Journal of the Franklin Institute, Vol 281, No 1, 1966, 51-72. MR 0187456