1. Die Berechnung der Drehschwingungen;Holzer,1921
2. Republished by J. W. Edwards Inc., Ann Arbor, MI (1948).
3. New method of calculating natural modes of coupled bending-torsion vibration of beams;Myklestad;Trans ASME,1945
4. Matrix solution of vibration of nonuniform beams;Thomson;J. Appl. Mech.,1950
5. Four pole parameters in vibration analysis;Molloy,1958