ABOUT THE ACCURACY OF ESTIMATED FREQUENCIES WITH THE PyFEST SOFTWARE. - Gillich, Gilbert-Rainer; Nedelcu, Dorian; Iancu, Vasile; Gillich, Nicoleta (Annals of 'Constantin Brancusi' University of Targu-Jiu. Engineering Series / Analele Universităţii Constantin Brâncuşi din Târgu-Jiu. Seria Inginerie, 2019)