[1] Mindlin R D. Stress functions for a Cosserat continuum. International Journal of Solids and Structures. 1965;1:265-271.
[2] Toupin R. Elastic materials with couple-stresses. Archive for rational mechanics and analysis. 1962;11:385-414.
[3] Koiter W T. Couple-stress in the theory of elasticity.1964;67:17-44.
[4] Yang F, Chong A C M, Lam D C C, Tong P. Couple stress based strain gradient theory for elasticity. International Journal of Solids and Structures. 2002;39:2731-2743.
[5] Park S K, Gao X L. Bernoulli–Euler beam model based on a modified couple stress theory. Journal of Micromechanics and Microengineering. 2006;16:2355.
[6] Kong S, Zhou S, Nie Z, Wang K. The size-dependent natural frequency of Bernoulli–Euler micro-beams. International Journal of Engineering Science. 2008;46:427-437.
[7] Ma H M, Gao X L, Reddy J N. A microstructure-dependent Timoshenko beam model based on a modified couple stress theory. Journal of the Mechanics and Physics of Solids. 2008;56:3379-3391.
[8] Ansari R, Gholami R, Shojaei M F, Mohammadi V, Sahmani S. Size-dependent bending, buckling and free vibration of functionally graded Timoshenko microbeams based on the most general strain gradient theory. Composite Structures. 2013;100:385-397.
[9] Tajalli S A, Rahaeifard M, Kahrobaiyan M H, Movahhedy M R, Akbari J, Ahmadian M T. Mechanical behavior analysis of size-dependent micro-scaled functionally graded Timoshenko beams by strain gradient elasticity theory. Composite Structures. 2013;102:72-80.
[10] Ansari R, Hasrati E, Faghih Shojaei M, Gholami R, Mohammadi V, Shahabodini A. Size-dependent bending, buckling and free vibration analyses of microscale functionally graded mindlin plates based on the strain gradient elasticity theory. Latin American Journal of Solids and Structures. 2016;13:632-664.
[11] Mohammadi H, Mahzoon M. Investigating thermal effects in nonlinear buckling analysis of micro beams using modified strain gradient theory. Iranian Journal of Science and Technology Transactions of Mechanical Engineering. 2014;38:303.
[12] Şimşek M, Kocatürk T, Akbaş Ş D. Static bending of a functionally graded microscale Timoshenko beam based on the modified couple stress theory. Composite Structures. 2013;95:740-747.