1. A. M. Freudenthal,The Inelastic Behaviour of Engineering Materials and Structures, Jonn Wiley & Sons, New York (1950).
2. T. Alfrey,Mechanical Behaviour of High Polymers, Interscience, New York (1948).
3. M. A. Biot, Theory of Stress-Strain Relations in Anisotropic Viscoelasticity and Relaxation Phenomena,J. Applied Physics, 25 (1954) 1385.
4. E. H. Lee, Stress Analysis in Viscoelastic Bodies,Q. Appl. Maths., 13 (1955) 183.
5. E. H. Lee and J. R. M. Radok, Stress Analysis in Linearly Viscoelastic Materials,Prc. 9thInt. Congr. Appl. Mech., Brussels (1956) 321.