On a system of equations arising in viscoelasticity theory of fractional   type
  We study a system of partial differential equations with integer and fractional derivatives arising in the study of forced oscillatory motion of a viscoelastic rod. We propose a new approach considering a quotient of relations appearing in the constitutive equation instead the constitutive equation itself. Both, a rod and a body are assumed to have finite mass. The motion of a body is assumed to be translatory. Existence and uniqueness for the corresponding initial-boundary value problem is proved within the spaces of functions and distributions. 
Teodor M. Atanackovic and Stevan Pilipovic and Dusan Zorica
math-ph math.MP