1. Dynamics of Elastic Systems;Nowacki,1963
2. Vibration Problems in Engineering;Timoshenko,1974
3. Dynamics in Engineering Structures;Kaloušek,1973
4. Introduction to Structural Dynamics;Biggs,1964
5. Vibrations of a beam carrying a concentrated mass;Goel;Jour. of Appl. Mech. (ASME),1973