2.K.V. Avramov, C. Pierre, N. Shyriaieva

"Flexural-flexural-torsional Non-linear Vibrations of Pre-twisted Rotating Beams with Asymmetric Cross-sections"
Journal of Vibration and Control, 13 (4), 329-364, 2007

1.E. J. Sapountzakis, G.C. Tsiatas

"Flexural-Torsional Vibrations of Beams by BEM"
Computational Mechanics, 39 (4), 409-417, 2007