Hosseini – Hashemi, Sh, M Fakher, and R Nazemnezhad. 2013. “Surface Effects on Free Vibration Analysis of Nanobeams Using Nonlocal Elasticity: A Comparison Between Euler-Bernoulli and Timoshenko”. Journal of Solid Mechanics 5 (4): 290-304. https://oiccpress.com/jsm/article/view/12438.