1. Gh. Buzdugan., L. Fetcu, M. Rades.: Mechanical Vibrations. Didactical and Pedagogical Printing House, Bucharest, (1982).
2. P. Cardei.: Models for Bodies with Unsteady Quality, Revue Roumaine des Sciences Techniques, Serie de Mecanique Appliquee, tome 45 1, Bucharest, 2000, pp.97-109.
3. http: /www. math. uaic. ro/~gani/depozit/EDP. pdf.
4. V. D., Radulescu.: Partial Differential Equations. Department of Mathematics, University of Craiova 2005, Romania.
5. Solid Works Material Library, (2012).