1. M. A. de Rosa and N. M. Auciello, “Free vibrations of tapered beams with flexible ends,” Comput. Struct. 60, 197–202 (1996).
2. E. T. Cranch and A. Adler, “Bending vibrations of variable section beams,” Am.Soc.Mech. Eng. 23, 103–108 (1956).
3. D. I. Caruntu, “On nonlinear vibration of nonuniform beam with rectangular cross-section and parabolic thickness variation,” Solid Mech. Appl. 73, 109–118 (2000).
4. T. D. Chaudhari and S. K. Maiti, “Modelling of transverse vibration of beam of linearly variable depth with edge crack,” Eng. Fract. Mech. 63, 425–445 (1999).
5. S. Abrate, “Vibration of non-uniform rods and beams,” J. Sound Vibr. 185, 703–716 (1995).