“The parametrical free vibrations of elastic systems. the analytical exact solutions” (2012) Analele Universităţii "Dunărea de Jos" din Galaţi. Fascicula XIV, Inginerie mecanică = Annals of “Dunarea de Jos“ University of Galati. Fascicle XIV, Mechanical Engineering, 19(1), pp. 55–58. Available at: https://ojs.ugal.ro/index.php/im/article/view/3694 (Accessed: 2 November 2026).