where D=Eh^3/(12(1-v^2 )) is the flexural rigidity of the SLGS. It should be noted that when the nonlocal parameter and surface constants are set to zero, the resultant relations given in Eq. (8) reduce to those of the classical plate theory. It is to be noted that the Poisson's ratio of the bulk and surface parts remain the same since the displacement field over the DLGS's thickness is considered to be continuous. Next, in order to derive the equations of motion of the DLGS, it is necessary to find the shear forces acting on the cross sections. The additional shear stress on the cross sections from Eq. (6) must be added to the classical terms of shear stress resultants. Finally the generalized differential equation for the circular DLGS with an eccentric hole and upper and lower surface layers will be derived as