On the set of harmonic solutions of a class of perturbed coupled and   nonautonomous differential equations on manifolds
  We study the set of $T$-periodic solutions of a class of $T$-periodically perturbed coupled and nonautonomous differential equations on manifolds. By using degree-theoretic methods we obtain a global continuation result for the $T$-periodic solutions of the considered equations. 
Luca Bisconti, Marco Spadini
math.CA