1. Timoshenko, S. P., Strength of Materials (1933).
2. Shapiro, G. S., On deformations of bodies with different resistances to tension and compression. Proc. Acad. Sci. USSR, Eng. Journ. Mech. of Solids. (MTT) No. 2 (1966).
3. Ambartsumian, S. A. and Khachatrian, A. A., Basic equations of the theory of elasticity for materials which resist tension and compression in a different manner. Proc. Acad. Sci. USSR, Eng. Journ. Mech. of Solids, (MTT) No. 2 (1966).
4. Ambartsumian, S. A., Equations of the plane problem of the elastic theory of materials with different moduli in tension and compression. Proc. Acad. Sci. Arm. SSR, Mechanics 19, No. 2 (1966) 1–19.
5. Ambartsumian, S. A. and Khachatrian, A. A., On the question of different moduli theory of elasticity. Report Acad. Sci. Arm. SSR, Mechanics 18, No. 4 (1969) 198–202.