2012. Considerations on the nonlinearity grade of the nonlinear mechanical elastic systems. 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 (Juni 2012), 13–18.